Surging Surging Surging!

I have an 05' w/ABS, and for about a year now I've done just about everything I can think of to eliminate a hot running surging problem. This symptom doesn't appear until the engine temp is over 200F, and is a lot more pronounced in 1st/2nd gear at the usual 4-5.5k rpm range, although it's still present but less pronounced in other gears at higher rpms. It's definitely a hot running problem...which pretty much means it runs badly during the summer months here in SoCal.

Here is a little history...

When I first got the bike, within a month or so I removed the flapper valve, PAIR system, and sync'd the starter valves. I also installed a set of Staintunes, and all tubing for the flapper and PAIR was yanked and capped off, and as far as I can tell I don't have a vacuum leak. Later on I added a PCIII USB and O2 Eliminators to help smooth out low rpm snatchiness, and when that helped but didn't eliminate the on/off transition, I also tried the Turbo City fuel pressure regulator. Never could get a working combination that totally got rid of the problem, so I decided to just live with it.

When my bike was apart this past September after a minor low-side, I went back to the stock fuel pressure regulator, and decided to replace the internal fuel filter and sparkplugs in case either might be a contributing factor to this problem. I also sent the PCIII back to Dynojet for testing, and even though they didn't find anything wrong with it, they sent me a brand new one. Also tested the O2 Eliminators...they weren't exactly 300 ohms if I remember correctly...just a little less at 290 ohms or so. Well within a 5% tolerance though...

This past weekend I loaded a zero PCIII map just to see what would happen, and once the bike got hot it surged even worse than before. It's tough to explain the surging, but it's as if the engine is stumbling...either from a severe lack of air or fuel.

Anyway, I'm about to give up and sell this thing as I can't believe I'm supposed to deal with a bike that runs like this. Any help comments would be appreciated...

How many miles on your '05? My advice would be to go COMPLETELY back to stock and put a few thousand miles on it, then see what happens.

Did you have this condition prior to you:

"When I first got the bike, within a month or so I removed the flapper valve, PAIR system, and sync'd the starter valves. I also installed a set of Staintunes, and all tubing for the flapper and PAIR was yanked and capped off, and as far as I can tell I don't have a vacuum leak."

These bikes have lean conditions all over as is and your mods could have made something worse! +1.gif

As far as a PCIII map goes, you may need a super fat(rich) area around your surge (3-5 k), but I would be worried that some hose or plug you moved or removed could be causing the extreme lean cond. that just running 02 eliminators could cure.

I would think you need to eliminate your mods as a source of the problem first, then hunt done the proper cure.

my $.02 :goofy:

NV2L8,

We met before, I think? Either the Tech Day at Steve's, or one of the SoCal flaf rides. Good to see you around.

Regarding the hot surge, well I have an '06 so admittedly our bikes are a little different there. But, my surging problems pretty much disappeared after about 5k on the bike....though you've probably put far more on it?

I don't know what else to offer besides that... +1.gif

Sounds to me like a faulty temperature sensor, Intake Air Temperature sensor or the Coolant Temperature Sensor. Most likely the coolant temp sensor since its is what measures the engine temp, and thats when your having surging issues at temp.

You should check for ecm codes - 7 blinks indicates off spec for the ETC sesor. Then measure the resistance between the yellow/blue (+) wire and the green/orange (-) wire terminals it should be 2.3-2.6 ohms at room temp (68f), then you need a harness to measure its output voltage - probably best done at a dealer who has the tool. It should be 4.75 - 5.25 volts. Unless you can rig up a way to test the voltage by piggybacking at the ECT connector or somthing.

I'm no expert, but the UK boys have found better running by resetting the Throttle Position Sensor (TPS). I'd explore that, in your position.

I have about 10.5K miles on the bike... And I'm not sure when the problem started, but it was a while ago. It definitely didn't have this problem when I first got it though, so it has to be something I modified or removed. And since the problem didn't surface shortly after a mod, I haven't been able to pinpoint it to anything specific. About a year ago I do remember the end of a work day commute, because when riding in 1st gear thru the last two blocks of the residential area near my home, it all of a sudden for the first time started surging. It was like, "okay, it hasn't ever done this before so what the heck is happening?"

Anyway, I was pretty careful when removing the flapper valve, PAIR system, and EVAC canister junk. I made sure to cap off everything except the fuel tank vent hose, but I still might have done something wrong. What is really puzzling is that during the winter months the cooler weather means the operating temp is usually between 175-200, and at these temps it's been running great. The first time the weather is warm and the bike gets over 200 in city traffic, then the surging becomes worse. Strange...

Going completely back to stock will be tough... That means re-installing the flapper and PAIR...both which can be done...but the area where the EVAC canister usually resides is now taken by a Stebel. I would also have to remove the Staintunes and install the stock exhaust.... All together it's a lot of work...

The bike is going to the dealer tonight because the right front shock is leaking from the seal. I'm going to be honest with the service manager and explain what I've done, what it's doing, and see what he has to say.

You know at least a couple of things:

1. It surges between 4.5 and 5.5k rpm.

2. It's surging, therefore it's running lean.

3. This is most likely either an air leak (which you seem to have ruled out), or insufficient fuelling.

Before you panic, and sell it or "blow the f$%ker up!", do this:

1. Save your current PCIII map to a different name.

2. Add some numbers to the map in the 4-6k rpm range (to richen it up), save it, and load it. (It sounds like it's just small throttle openings, so start with those first).

3. Go for a ride.

4. If it's not right, then repeat until it's more betterer and acceptable.

5. If for some reason it gets worse (unlikely), then it's actually running too rich, and you need to put lower figures in the map.

It's not RocketScience, so it's easily fixed. You have nothing to lose by fiddling around with your mapping, because you've got the saved one to go back to, and it's relatively hard to muck it up, as long as you don't change too many factors at once, keep each change small(ish), and note what you did.

If this is all too hard, then you need to have it dynoed with an EGO sniffer.

NVR2L8I have about 10.5K miles on the bike... And I'm not sure when the problem started, but it was a while ago. It definitely didn't have this problem when I first got it though, so it has to be something I modified or removed. And since the problem didn't surface shortly after a mod, I haven't been able to pinpoint it to anything specific. About a year ago I do remember the end of a work day commute, because when riding in 1st gear thru the last two blocks of the residential area near my home, it all of a sudden for the first time started surging. It was like, "okay, it hasn't ever done this before so what the heck is happening?"

Anyway, I was pretty careful when removing the flapper valve, PAIR system, and EVAC canister junk. I made sure to cap off everything except the fuel tank vent hose, but I still might have done something wrong. What is really puzzling is that during the winter months the cooler weather means the operating temp is usually between 175-200, and at these temps it's been running great. The first time the weather is warm and the bike gets over 200 in city traffic, then the surging becomes worse. Strange...

Going completely back to stock will be tough... That means re-installing the flapper and PAIR...both which can be done...but the area where the EVAC canister usually resides is now taken by a Stebel. I would also have to remove the Staintunes and install the stock exhaust.... All together it's a lot of work...

The bike is going to the dealer tonight because the right front shock is leaking from the seal. I'm going to be honest with the service manager and explain what I've done, what it's doing, and see what he has to say.

I'm not sure if I would worry about the exhaust, even though it should make a lean condition leaner. All (or one of) the vacuum line work you mentioned could be an issue, even a blocked/plugged tank vent could cause problems when it's hot enough for excessive fuel evap.! Sorry your having issues and good luck. :thumbsup:

Thanks for the replies... After work I'm taking the bike to the dealer for the leaking shock, and depending on what the service manager says just might let the dealer figure it out. I trust this dealership since they're small and family owned...not like the other big Los Angeles area dealerships. Some good advice here though and I appreciate the help...I'm leaning towards a vacuum leak or maybe I plugged something I shouldn't have.

NVR2L8Thanks for the replies... After work I'm taking the bike to the dealer for the leaking shock, and depending on what the service manager says just might let the dealer figure it out. I trust this dealership since they're small and family owned...not like the other big Los Angeles area dealerships. Some good advice here though and I appreciate the help...I'm leaning towards a vacuum leak or maybe I plugged something I shouldn't have.

I hate it when I plugged something I shouldn't have. +1.gif

Good luck. :thumbsup:

I have pretty much the same setup as you, although I'm running an 02.

Staintunes, K&N, TurboCity FPR, and PCIII-USB with the poor-man's O2 elims (330 Ohm Resistors).

The PCIII was the last thing I installed, and since then I have taken it back off due to gas mileage issues until I can get a custom map done at a DynoJet center. Other than that, it ran pretty nice with a map that was sent to me from a member on these boards. No surging, extremely smooth VTEC transition, nice low end delivery, and no "snatchiness".

The bike ran really well after installing the TC-FPR as well, so I just dropped back to that to get a little better gas mileage for the commuting I do.

I still have my PAIR system on and have only disconnected the vaccuum line for the flapper valve.

If you would like to try a different map, it may clear up some issues for you. At least with this map, if you still have problems, you should only have to re-install the PAIR and you will be very close to the same mods as me. May help in troubleshooting.

If you want to give it a try, let me know and I can email the map to you.

Get it mapped on a dyno that has a broadband ego and 3 gas analyzer tied to it. Use the eddy current to duplicate conditions and see what happens when it surges. (Lean/rich, timing) adjust as needed.

NVR2L8Thanks for the replies... After work I'm taking the bike to the dealer for the leaking shock, and depending on what the service manager says just might let the dealer figure it out. I trust this dealership since they're small and family owned...not like the other big Los Angeles area dealerships. Some good advice here though and I appreciate the help...I'm leaning towards a vacuum leak or maybe I plugged something I shouldn't have.

NVR, this may be the only area that I can actually provide some advice and or guidance. I have a similar set up although I have Remus exhaust, K&N and O2 elims. I experienced worse than normal surging after I installed my O2 elims. For somme reason the CPU doesn't always recognize the open loop (or is it closed loop) at start up so you have to turn the key to the on position let it go through it's FI whine and then turn it off. Wait a couple seconds and tunr it back on and then start it. I do this every time now and have no problems. Others have had the same issue. Give that a try without the PCIII first befoe you get drastic. Good luck.

All good advise. For the heck of it, toss in some FI cleaner, also. Slight chance that it may help.

As said before....return the bike to stock and begin your troubleshooting there. I would leave the Staintunes on as they probably have nothing to do with your problem. Who knows, returning it to stock may cure the issue. Good luck.

I have an '03 and other than the Staintunes and a Sargent seat it is stock. No problems in 23,000 miles.

Update to my surging issue!!!!

I’ve posted here on VFRD about an annoying surging problem, and I think I might have stumbled onto something.

Here’s a quick synopsis...

I started having a surging problem sometime last summer. It usually only happened when the bike temp reached 200F or higher, and was very pronounced when riding at high rpm at a constant speed in first gear. My bike has been de-flapperized, un-PAIR’ed, and the EVAP canister has been removed, and other mods include Staintunes, K&N air filter, PCIII USB and O2 Eliminators. After my low-speed crash last September I figured it was a good time to do a few things that I thought might take care of the problem, so I checked all vacuum lines and capped-off fittings for leakage, checked vacuum and fuel lines for kinks, replaced the fuel tank fuel filter, replaced the sparkplugs, beefed up the 30-amp fuse link with 12 gauge wire, and re-synced the starter valves. Dynojet even sent me a new PCIII USB after I sent mine in for testing. About a month ago I re-connected the flapper valve, and since I didn’t want to re-connect the PAIR system, I installed a set of aluminum PAIR valve covers. None of these things had any affect or fixed the surging problem…

A few weeks ago I tried something else after reading a post here on VFRD, and I think what I did all but eliminated the surging problem. I can’t say that the surging is completely gone, because once in a while when the engine is at 200F or higher, I can occasionally feel just a slight amount of stumbling while holding a steady throttle in first gear, but it’s definitely a lot better. So it’s not a 100% fix...more like a 90% fix which is great and I can live with it.

What was the fix you ask? It was the velocity stack placement…

At some point after having the airbox apart and putting it back together, I didn’t think to see how the stacks were originally placed at the factory, and when I checked VFRD the consensus here was that they should be front/short and rear/tall. In one of H.S.’s tutorials though he has the placement staggered, except just the opposite as what I show below. Anyway, ever since last summer I’ve had the velocity stacks with the short in the front and the tall in the rear, and I’ve been chasing a frustrating surging problem.

After reading another post though, I switched my stacks to this configuration which seems to be how the manual depicts them and how they are installed at the factory.

Left Front: Short

Right Front: Tall

Left Rear: Tall

Right Rear: Short

Here is the thread: http://www.vfrdiscussion.com/forum/index.p...c=30771&hl=

I don’t know why this makes a difference, but it does seem to affect how the bike runs. So if you’re running the stacks as front/short and rear/tall, and are experiencing low speed high rpm surging, then I suggest trying the stacks in this configuration. It worked for me…

NVR2L8Update to my surging issue!!!!

After reading another post though, I switched my stacks to this configuration which seems to be how the manual depicts them and how they are installed at the factory.

Left Front: Short

Right Front: Tall

Left Rear: Tall

Right Rear: Short

Here is the thread: http://www.vfrdiscussion.com/forum/index.p...c=30771&hl=

I don’t know why this makes a difference, but it does seem to affect how the bike runs. So if you’re running the stacks as front/short and rear/tall, and are experiencing low speed high rpm surging, then I suggest trying the stacks in this configuration. It worked for me…

I believe that as the potential source of your problem, good for you finding it!

I've seen the "shorts in front talls in rear" recommendation before, but none of the half dozen factory Vtecs I've looked at had this config from the factory and I know Honda spent a lot of time setting up our air boxes! :thumbsup:

NVR2L8I switched my stacks to this configuration which seems to be how the manual depicts them and how they are installed at the factory.

Left Front: Short

Right Front: Tall

Left Rear: Tall

Right Rear: Short

I don’t know why this makes a difference, but it does seem to affect how the bike runs. So if you’re running the stacks as front/short and rear/tall, and are experiencing low speed high rpm surging, then I suggest trying the stacks in this configuration. It worked for me…

Very interesting. I know when I stuck 330 ohm resistors in my O2 sensor wires, the surging was absolutely horrible. Almost to the point of dangerous when traveling around town in 1st and 2nd gear. The only work around was to get the bike to start in default mode, which involved turning the bike on and off quickly a few times before starting it.

After putting on quite a few miles with the resistors in place, the surging has gotten better. I can still tell it's there, but it's no where near as bad as before. I always figured the ECU just "relearned" everything and fixed it for me. I'll have to give this velocity stack swap a try and see if it eliminates the surging for good. :thumbsup:

Darth BlingAfter putting on quite a few miles with the resistors in place, the surging has gotten better. I can still tell it's there, but it's no where near as bad as before. I always figured the ECU just "relearned" everything and fixed it for me. I'll have to give this velocity stack swap a try and see if it eliminates the surging for good. :thumbsup:

I wish that was the case, but our ECU's do not have that ability (to learn). sad.gif

SWEET! :thumbsup:

After putting on quite a few miles with the resistors in place, the surging has gotten better. I can still tell it's there, but it's no where near as bad as before. I always figured the ECU just "relearned" everything and fixed it for me. I'll have to give this velocity stack swap a try and see if it eliminates the surging for good. :thumbsup:

Please post your results after trying the stack swap...I rode my bike for about 2 weeks after the change to make sure the stack placement made a difference. I still get some slight surging now and then, but as quicknick already mentioned, it also helps to change your startup routine. Turn the ignition ON and let the fuel pump prime, and then OFF and back ON. Crazy...but it works.

I also re-connected the flapper. I didn't notice any performance gain with it disconnected, and I quickly tired of hearing the intake suckage noise. It also didn't make any difference with the surging, but with it re-connected it does make the on/off throttle a little snatchier. Still, my flapper is back to stock and I'm leaving that way.

just like a computer, put it back to stock, then start adding things one by one untill it breaks. dealer will take your money

I remember wondering about that due to the bad drawing in the tech manual, but at the same time I don't recall finding my stacks installed that way when I first took the bike apart.

Its been a long time, but I'm pretty sure the length of the plastic differs front to back to make up for the difference in length in the intake runners below them. Anyone with a brand new VTEC want to take theirs apart for the first time to look, or does someone want to measure the difference between intake length in front and back?

From an engineering standpoint, at lower RPM where you're having issues the stack placement shouldn't affect surging for two reasons. One is that the air is moving well below the point where the intake would experience sonic choking, and its way, way too short compared to diameter at too low of a speed for friction to be significant...so runner length doesn't matter. The second is that the plastic stack is upstream from the butterfly valve. If its not entirely or almost entirely open, its interfering with the flow (by design, fuel mixing needs turbulence) and so again, the runner length doesn't matter.

This is why it doesn't matter that your airbox is discombobulated for the starter valve sync...air is too slow for significant friction or choking to occur anyway. Its also why your surging isn't entirely gone wink.gif

I would suspect that your bike might have new issues at or near full throttle with different intake lengths...assuming that you're not remembering original placement better than I am :unsure:

I opened up an 02, 04 & 06 for the first time each and all were as shown in the post here: short and tall on the front cyl. None of the Vtecs I've ever opened had shorts or talls on the same head! wink.gif

Well, I just had the same problem with my 05'

My 05’ was running perfect before I just did a full tune up. I checked the valves, changed the plugs, changed the air filter, replaced the coolant, replaced the brake fluid and pads and replaced the clutch fluid.. When I was done I got on the bike and she was smoother than she had ever been, until about 15 or 20 min later then she started to surge very noticeably at all steady throttle openings. She was almost impossible to ride in tricky throttle situations. She had never surged before. BTW, all plumbing on the bike is stock.

Since I did not have to change any lifters I figured that I put something back together wrong.

At that point I figured I had a vacuum problem, either a leak or a pinched vacuum hose. Well it turned out I had two pinched hoses, one the vacuum line that runs around the front of the air box to the vacuum canister just forward of the air box. The line was pinched under the air box. It is kind of a tricky location for you can’t see the line when you place the air box down and on mine it appears to have compressed when it was caught under the air box when I reinstalled the box.

The second pinched line that "may" have been pinched was my coolant overflow line from the radiator on the right side traveling across the almost same location as the vacuum line as it heads over to the left side of the bike to the coolant reservoir.

After I fixed both of those all the surging was gone.

Oh ya, my stacks are small front, tall rear, it is how it came and I left them that way.

NVR2L8I have an 05' w/ABS, and for about a year now I've done just about everything I can think of to eliminate a hot running surging problem. This symptom doesn't appear until the engine temp is over 200F, and is a lot more pronounced in 1st/2nd gear at the usual 4-5.5k rpm range, although it's still present but less pronounced in other gears at higher rpms. It's definitely a hot running problem...which pretty much means it runs badly during the summer months here in SoCal.

Here is a little history...

When I first got the bike, within a month or so I removed the flapper valve, PAIR system, and sync'd the starter valves. I also installed a set of Staintunes, and all tubing for the flapper and PAIR was yanked and capped off, and as far as I can tell I don't have a vacuum leak. Later on I added a PCIII USB and O2 Eliminators to help smooth out low rpm snatchiness, and when that helped but didn't eliminate the on/off transition, I also tried the Turbo City fuel pressure regulator. Never could get a working combination that totally got rid of the problem, so I decided to just live with it.

When my bike was apart this past September after a minor low-side, I went back to the stock fuel pressure regulator, and decided to replace the internal fuel filter and sparkplugs in case either might be a contributing factor to this problem. I also sent the PCIII back to Dynojet for testing, and even though they didn't find anything wrong with it, they sent me a brand new one. Also tested the O2 Eliminators...they weren't exactly 300 ohms if I remember correctly...just a little less at 290 ohms or so. Well within a 5% tolerance though...

This past weekend I loaded a zero PCIII map just to see what would happen, and once the bike got hot it surged even worse than before. It's tough to explain the surging, but it's as if the engine is stumbling...either from a severe lack of air or fuel.

Anyway, I'm about to give up and sell this thing as I can't believe I'm supposed to deal with a bike that runs like this. Any help comments would be appreciated...

My 04vfr did the same thing, really bad when its hot and im in traffic thats moving slow, 10-40mph and in 1, 2, 3gears my bike has always did this and is stock. i just removed the 02sensors and it ran great for a few days, then today in town it was acting up really bad, makes me nerves to ride it. It will also do this at highway speeds, feels like its slowing down so you give it more throttle but nothing happens then a little more and all the sudden it jumps forward. My bike was bought brand new 3months ago. Its a piece of #!$@.

Mines just started acting up - my hunch is a TPS or a sticking cold start valve. Or it may be as simple as a hose off somewhere.

I'll check it out this weekend and post my findings here.

If anyone has any other suggestions to look for, please....... I'm open to input.

Thanks

Hey NVR2L8,

Glad that you've seemed to "fix" your issues.

FWIW, I went to a PCIII a few years ago and before I did, I did a fair bit of research on who seemed to be most happy with their PC's. It was pretty apparent at the time that the people that were having the best results with their PC's were those that had custom maps made. I went that route and the improvement was very worthwhile...........i.e. well made custom map is the way to go IMHO. I have a friend with an '04 and he was having the same frustrating hesitation/surging issues that many of us have experienced...got a PC and tried DJ's maps and a map from a member here with no consistent improvement in general with any of these maps. Finally got him to try my map(he was concerned that since his bike was setup different than mine it wouldn't work well) and he's a happy camper now.........issues virtually gone.

PM me if you need more info,

Craig

Wow. This is starting to sound familiar. I just posted a fix under the vtech electrical problems that sounds a lot like this. Temperature sensitive surging/ poor steady state throttle response. I put in o2 eliminators in an effort to get rid of the surge, and it got better, but never fully went away. Finally it started to get really bad. The fix was maintenance of the engine management electrical connectors. Several folks posted that their problems started or got worse when they worked on stuff on the right side of the bike – maybe moved the harness? Someone else who is having a problem needs to try this and confirm. Wouldn’t it be interesting if all of the surging issues were nothing more than a high resistance engine management connection?

http://www.vfrdiscussion.com/forum/index.p...st&p=429571

I'll be VERY interested to see if the issue goes away with the recent harness recall........

In reference to moving the velocity stacks......this can have a profound effect on engine perfomance as the length / diameter of the stacks affect intake air flow speed. Taller / narrower increase speed and shorter / wider reduce the speed.

I've been meaning to post my recent findings...

If you've read thru the entire thread where I discussed some of the mods I have done to my bike, as well as some of the things I did that had an affect as I tried to eliminate the hot running surging, one of the first things that stood out as a partial fix were the velocity stacks.

The arrangement of the velocity stacks in this configuration, “Left Front: Short”, “Right Front: Tall”, “Left Rear: Tall”, and “Right Rear: Short”, made a definite difference. I commute to work on my VFR every day, so I believe I ride it enough to be able to tell when something makes it run better or worse. The velocity stacks in the above arrangement seemed to help but didn’t totally eliminate the hot surging.

I had already done most of the electrical mods, such as the 30-amp fuse fix, left-side blue connector ground wire, and so on, but since my bike is fairly new and the wiring seems to be okay so far, I thought of these mods/upgrades as preventive measures since none of them affected the surging. What I didn’t realize is that my particular surging problem was related to the electrical system.

About 3-4 months ago I noticed that my barely 2-year-old battery was starting to act up. In the summer mornings it seemed as though the engine was becoming harder to start, and when I hit the starter button it took several revolutions until the engine started. Work with me on the sound effects here, but it was like “woo woo, woo woo, woo woo, woo woo, vroom!!!” Slow tickover until it finally gone caught and started. I also had an instance where I stopped at a traffic light, and the idle dropped to about 500 rpms for about 10 secs before it finally came back up. I finally decided to just replace the battery when the bike barely started after the third of several errands I had run during my work lunch break.

I went with an FTZ-14S from motorcyclebatteries.com, which is the same size as the stock battery, but has a few more cold cranking amps. The first time I hit the starter button after installing it the engine fired up with a “woo woo, vroom!!!”, so I know my slow starting was due to the battery. Maybe my stock battery is somehow defective and just doesn’t hold a charge correctly...?

The next morning when I rode to work I didn’t even think about the new battery, until I noticed the engine seemed to be running a lot smoother. During my 40 minute commute I didn’t notice any running surging whatsoever, although I really didn’t believe the battery could have been the source of the problem. So, for the next week I decided to really focus on how the bike ran in really hot temperatures. Well, I installed the new battery a little over two weeks ago, and in my particular case I think that was the problem. We’ve had some pretty hot temps here in SoCal for a while now, and there have been only a few times where I’ve noticed only a very slight surge or a slight on/off throttle dead spot. But it’s nothing compared to how it ran before…it’s a night and day difference. In fact, I am amazed at how smooth it runs now. I can run in 1st gear at 5-6K, at engine temps well over 200F, and it doesn’t surge at all. Nada...

A few days after installing the battery I decided I had better also do the monitor wire fix, as although my voltage below the high level per the service manual at about 15.1 – 15.2 volts, I was worried that maybe the battery had gotten overcharged and that is what made it fail so quickly. After the wiring fix my voltage is now steady at 14.2 – 14.3 volts. I really don’t think the running voltage was the problem, as the engine definitely ran better after the new battery was installed, but the same after the monitor wire fix.

So…I think my hot surging issue was electrically related, but I’m not sure how. The only thing I can figure is that the overall electrical system would become degraded after the bike fully warmed up, and somehow the battery was part of the equation, although I don't see how the battery could change characteristics depending on engine temperature. Anyway, my advice is that if you experience a similar problem, do yourself a favor and perform all of the wiring fixes/upgrades, but first have the battery checked as a potential source.

I have an 02 vfr all stock and at the last track day I noticed a surge or hesitation while in 2nd gear between 9500 -10000 rpm. Last weekend on the street in the twisties I noticed the same problem at exactly the same rpm's and while in 2nd gear. Shift to third and it goes away. The temp will go up to around 218 at times as well. Otherwise the bike run great. Obvious concern while leaned over in the corners. Does this sound like a sensor problem? I want to give the dealer as much info as I can to help solve the problem. A mechanic I am not. Thanks for any help you can give. CIRV

Baileyrock

NVR2L8Update to my surging issue!!!!

After reading another post though, I switched my stacks to this configuration which seems to be how the manual depicts them and how they are installed at the factory.

Left Front: Short

Right Front: Tall

Left Rear: Tall

Right Rear: Short

Here is the thread: http://www.vfrdiscussion.com/forum/index.p...c=30771&hl=

I don’t know why this makes a difference, but it does seem to affect how the bike runs. So if you’re running the stacks as front/short and rear/tall, and are experiencing low speed high rpm surging, then I suggest trying the stacks in this configuration. It worked for me…

I believe that as the potential source of your problem, good for you finding it!

I've seen the "shorts in front talls in rear" recommendation before, but none of the half dozen factory Vtecs I've looked at had this config from the factory and I know Honda spent a lot of time setting up our air boxes! :thumbsup:

MY o6 vfrabs has both short ones in the front and both tall ones in the rear , they had never been touched from the factory

Okay I just cjanged the spark plugs and airfilter in my 2006 model. didnt even pull a fairing or raise the rear of the tank. The front plugs are subseptible to dirt so blow out well with compressed air, the rear plugs are kept much cleaner. all my plugs removed looked like some slight wear but the gaps were still in spec at 27,000+ mile. I think 35,000 is an easy, course my bike has been subjected to leaded race fuel which tend to clean everything pretty.

But the spark plug wells are like 2 feet Deep, okay not really, more like 7 inches deep, a magnet is a requirement, I couldnt believe how deep they wer though. disconnecting the direct coil connectors took alot of thought. They have a squeese release mechanism, pul too hard to pull apart. I used a large flat blade on the seam where the male female join , and slightly twist whle squeezing the release.

But the Velocity stacks, assuming all the airboxes are the same, its quite simple, the airbox bottom in the rear is much lower than in the front, the tall stacks go there where the bottom is deeper, in the front has a raise bottom so shorts go there. BY stalling this way all the tops of the stacks are the same height for smoth air flow across them, if you put the tall ones on the higher bottom and any low ones on the deeper bottom.

'

your just going to create alot of turbulance, and wont get smooth air flow.

my airfilter barely could get light through it

I'm tempted to crack open my airbox to look at the stacks.

The velocity stacks are designed to give each runner the same length. All modern engines are this way, same for intake manifolds and exhaust headers. Thats why we have spaghetti exhaust plumbing.

Edit,

It is very good advice about the battery and very intriging. I see honda autos that start a little slow but still start. The abs or srs light will be on with many control unit failure codes. A weak battery is the source of the problem 9 times out of 10.

soichiroI'm tempted to crack open my airbox to look at the stacks.

The velocity stacks are designed to give each runner the same length. All modern engines are this way, same for intake manifolds and exhaust headers. Thats why we have spaghetti exhaust plumbing.

Edit,

It is very good advice about the battery and very intriging. I see honda autos that start a little slow but still start. The abs or srs light will be on with many control unit failure codes. A weak battery is the source of the problem 9 times out of 10.

I had my airbox lid off today and my bike has the tall's in the rear short's in the front.

K&N with 28k miles and an opened up airbix lid and the filter wasnt even dirty.

soichiro

soichiroI'm tempted to crack open my airbox to look at the stacks.

The velocity stacks are designed to give each runner the same length. All modern engines are this way, same for intake manifolds and exhaust headers. Thats why we have spaghetti exhaust plumbing.

Edit,

It is very good advice about the battery and very intriging. I see honda autos that start a little slow but still start. The abs or srs light will be on with many control unit failure codes. A weak battery is the source of the problem 9 times out of 10.

I had my airbox lid off today and my bike has the tall's in the rear short's in the front.

K&N with 28k miles and an opened up airbix lid and the filter wasnt even dirty.

28,000 and not dirty, does that kind make ya wonder about the filtering?

cirvI have an 02 vfr all stock and at the last track day I noticed a surge or hesitation while in 2nd gear between 9500 -10000 rpm. Last weekend on the street in the twisties I noticed the same problem at exactly the same rpm's and while in 2nd gear. Shift to third and it goes away.

I've had that problem on my '02 once or twice too: 2nd gear - Wide Open Throttle and high revs. The engine appeared to cut out for a heartbeat and then come back. This was way back in 2002, and it's never done it since.

adam79My bike does the same thing, really bad when its hot and im in traffic thats moving slow, 10-40mph and in 1, 2, 3gears my bike has always did this and is stock. i just removed the 02sensors and it ran great for a few days, then today in town it was acting up really bad, makes me nerves to ride it. It will also do this at highway speeds, feels like its slowing down so you give it more throttle but nothing happens then a little more and all the sudden it jumps forward.

This is the exact behaviour my '02 exhibits. You give it a little and there is nothing, you give it some more and then suddenly the power appears in an instant.

Somebody mentioned stuck fast wax idle units. I so wish I had a wideband O2 sensor in my pocket all the time so I could just stick the fecker down the exhaust pipe and see if it's running lean, or rich!

Just to add my input for the heck of it, my '02 has had the hesitation almost all along...although I really started noting it last summer (coincidentally after reading about it here). I always notice it around town, between 4-5k rpm under very slight throttle. Some days its worse than others, but one thing I did notice is that in the mountains and higher altitudes is where itd seem to be noticably worse. I now have 36k miles on it and everything is totally stock besides the BMC air filter which i just changed from the former KN I had in there. I havent messed with the flapper, PAIR, or any other emissions equipment at all. Stock exhaust as well. I did adjust my starter valves two summers ago just for the heck of it because it was mentioned on here so much at the time. My velocity stacks are short/tall in front and tall/short on the rear head. Ive double checked this a couple times, since thats how the Honda service manual illustrates they should be.

And to answer someones question earlier, I did recently have the wiring recall done, and no apparent change in the surging issue afterwards. Ive just gotten used to the fact that this is characteristic of the bike and is probably due to its super lean setup from the factory.

Like many agree, the FI setup on these bikes is super lean....a little too lean I believe, so much so that it borders on poor drivability issues. I just figure this surging is just another result of this.

Oh, and ive also changed my wax unit over this past winter just because ive heard of numerous issues with it on others bikes, and i had it torn apart anyways in that area. This also did not help or effect the surging....its still there just like it was before.

Adam30 said ((My velocity stacks are short/tall in front and tall/short on the rear head. Ive double checked this a couple times, since thats how the Honda service manual illustrates they should be.))...

Are you sure about that? Mine are short in front and tall in the rear. If you look at the 2002 VTEC service manual, it's not clear about this. It shows 4 stacks and some are rotated which may make them appear taller/shorter but it's not clear where they go. However, if you look at the VFRD Parts List and navigate to the Air Cleaner, it shows 2 part numbers and they are the one part number in the front and the other part number in the rear. I'd say that clearly indicates that they're supposed to be short in front and tall in the rear.

Maybe this is the source of your trouble?

Hey, just got your post from the other thread to look at this one, lol.

Ive presented this issue on a couple of different threads and was starting to lose track on where i was, lol.

But anyways, that is interesting....and i know it's been kind of a debate here before. THe way i saw the illustration in the service manual was LF and RR were to be short. It is "fairly" clear in my manual, but not perectly clear. The one thing i have noticed the past couple times of disassembly was that the little index marks they put on the stacks dont always seem to line up with the corresponding marks on the airbox.

But, just looked at the VFRD Parts list, which ive never done before....and you're correct, its showing both #6's up front and two #7's in the back.

Im going to go back and look....I swear there were guys saying that their bikes were LF-short RR-Tall and that they havent been touched from the factory. But i guess ive heard it both ways now that i think of it.....

Hmmmm.......

Adam30Im going to go back and look....I swear there were guys saying that their bikes were LF-short RR-Tall and that they havent been touched from the factory. But i guess ive heard it both ways now that i think of it.....

Hmmmm.......

That would be me for one, I opened no less then 6 virgin 6th gens and every one was like mine and had the LF- short RF-tall set-up like the manual shows.

A parts micro fish shouldn't be used to correctly assemble anything IMO, even if it happen to be correct! :wheel:

There was at least one other member who was having new surge issues after some repair work he did, saying the bike just would not run right. He had the short front set-up and change it to the short/tall front and said it cured all his issues. :happy:

I've had this set-up for 60k miles w/o a single surge issue. +1.gif

Sorry....I did mean LF and RR short. That's what the service manual seems to indicate as well, but it is a bit vague

My 04 and my buddies 06 both have a mixed config (short /tall front and back). When we did the TBCFPR mod I didn't pay attention and put mine back short-front tall-back and it ran like crap. Switched them back and all was pretty good only a little surging. I did call TBC and told them I still had a little surge, they had me try an FPR that had 2lbs more pressure then the first one they sent me. That pretty much fixed everything; although it did increase the puch on the vtec transition a bit.

Enzed has it right. It's a lean condition....all you have to do is find it. I think I would try the stock exhaust first & see what happens.

To follow up with this thread incase some of you didnt see my post in my other thread from last week, the official word from Honda is that the velocity stacks are to be both short in front and both tall in the rear.

Ressurecting this thread so as not to open another...

Having the typical surging or dead-spots at 3500 and 4500 RPM... I can live with those, almost, but what IS worrying me is the VTEC transition. It seems to be confused somewhat, and the take-up / back-off point seems to cover a wider range of RPM... from 6800 to 7500 almost, and when in this range, pushing the bike hard, and holding a steady throttle, it will surge, and at times and given how hard I like to push the bike, it is more than annoying at times... it seems to do it at any RPM in VTEC mode at steady throttle once the bike is hot... fix over these last few weeks that it's been misbehaving is engine off and start her up again before the FI finishes its start-up check/routine... doesn't completely eliminate it but almost...

Drives me batty to say the least...

2003, K&N, apart from that, it´s stock... last tech inspection for road worthy certificate showed the bike emitting CO way above spec, changed to K&N shortly aftewards... I would say the surgin has gotten worse since the weather has got hotter and since the K&N...

The only other time I experienced surging it was way worse and due to a faulty stator = flat battery... but the RPM needle would jump up and down radically and the bike wouldn't start... new stator should have fixed that... but I mention it as low charge can produce poltergeists in the FI system.

I'm wondering if new plugs and battery (this may have suffered from the stator failure) would help but I think it's something else... maybe the K&N... there are so many factors to consider...

OK so I lifted the fuel tank to see whether anything jumped out at me and I noticed the rubber hoseline which goes to the copper coloured vacuum thingy which I believe operates the flap was not connected. Could this be part of the reason behind the sudden appearance of these surging symptoms?? I can't be 100% sure whether I left it disconnected after installing the K&N filter or whether it sprung off on lifting the tank this afternoon. If this being disconnected can cause my symptoms, then it's clear I somehow didn't connect it up properly (I'm sure I recall connecting it) when installing the K&N, as I believe I have been noticing the symptoms since then...

I guess I will find out after this upcoming weekend's trip up to Valencia and across to Madrid and back... will report back...

Best of luck Auspanol, we both seem to have our fair share of bike issues... I'm on the ragged edge at the moment about to pull the plug and swap for a 5th gen... I'm holding out at the minute though!

What is it this time Steve??

Well. 5 or 600 km today and the f%$#er still surges when maintaining steady throttle in the VTEC RPM range... not as badly perhaps, but I guess I just avoided living in the VTEC RPM range and when up there tried to not hold the throttle steady too often... so it's all relative.

It just jerks around like a bucking bull and at full lean and 10,000 revs this is not cool...

I wonder if the Cat and other things get clogged over time and stoich-o-matic mode or whatever it's called becomes fauled somehow... what I don't want is to now go down the de-flap, de-O2, de-this, de-that road to later find that it still surges...

BTW; velocity stacks: short up front tall up back... never been touched.

Have you considered that it might be the clutch? You really have to watch the clutch on VFR's. :biggrin:

Damn... all these electrical and surging issues, you never hear about this sort of thing from the 5th gen bikes... do you? :biggrin:

Pete McCraryHave you considered that it might be the clutch? You really have to watch the clutch on VFR's. :blink:

HAHAHAHAHA, yep you do :laugh: :laugh: :laugh: Funny stuff Pete :biggrin:

If you as me, the VTEC engagement spot is a tough area to try and hold a steady rpm, and I would think a little surging would almost be normal as the engine transitions from 2 to 4 valve operation. I don't know if you're running a Power Commander, but I have a PCI USB and with Cozye's map, the VTEC engagement is a lot less abrupt and manageable. I still get a little surging though, so I try to either be above or below the VTEC sweet spot.

Having said that, aside from the VTEC surge, I think most of my surging problems have been caused by other electrical issues. If you read my posts, you'll see that I noticed a big improvement when I replaced the battery, and just recently I noticed that my low speed mid rpm problems seemed to be coming back again. I thought a new battery was in my future...

Just last week though, my Starter Relay fried and the connector mating to it was melted, but after I replaced both I noticed another improvement in how the bike ran.

Anyway, if the VTEC area is the only place where you have surging problem I suggest a Power Commander and Coyze's map. If you have surging in other areas, I'd start looking at electrical improvements such as Tightwad's VFRness.

cruzinaz

Pete McCraryHave you considered that it might be the clutch? You really have to watch the clutch on VFR's. :blink:

HAHAHAHAHA, yep you do :laugh: :laugh: :laugh: Funny stuff Pete :biggrin:

Do tell...???

NVR2L8If you as me, the VTEC engagement spot is a tough area to try and hold a steady rpm, and I would think a little surging would almost be normal as the engine transitions from 2 to 4 valve operation. I don't know if you're running a Power Commander, but I have a PCI USB and with Cozye's map, the VTEC engagement is a lot less abrupt and manageable. I still get a little surging though, so I try to either be above or below the VTEC sweet spot.

Having said that, aside from the VTEC surge, I think most of my surging problems have been caused by other electrical issues. If you read my posts, you'll see that I noticed a big improvement when I replaced the battery, and just recently I noticed that my low speed mid rpm problems seemed to be coming back again. I thought a new battery was in my future...

Just last week though, my Starter Relay fried and the connector mating to it was melted, but after I replaced both I noticed another improvement in how the bike ran.

Anyway, if the VTEC area is the only place where you have surging problem I suggest a Power Commander and Coyze's map. If you have surging in other areas, I'd start looking at electrical improvements such as Tightwad's VFRness.

Have the VFRness, done the blue connector fix (also thanks to Tightwad). New stator. Many connectors and such cleaned up with dielectric spray.

Have run a series of checks with multimeter. Solid readings. Even let the bike heat up, and on the centre stand in neutral, checked the readings up in the VTEC RPM range... solid as a rock.

I do notice a slight flat spot at 3500 and 4500 RPM. Typical on this model, but these don't bother me so much. What bothers me is the much stronger surging above 6800 RPM, not just in the transition range, but at 8500 or 9000 or wherever in the VTEC range if holding steady throttle or making minor imputs to throttle...

I am aware and do agree that the electrical system can be responsible, in reference to bad charging system... when my stator fried the surging was tremendous... way moreso than what I'm noticing now, and this, coupled with the solid multimeter readings, makes me rule out the typical stator, R/R and battery area...

vfr_steveDamn... all these electrical and surging issues, you never hear about this sort of thing from the 5th gen bikes... do you? [image: emoji3.png]

You can have a bad time of it electrically with the 5th gen... especially the 98-99 years. But it tends just to be the R/R... easy diagnosis and fix. Only seen one 98er among those over here in the Spanish VFR Club, fry its stator.

AuspañolHave the VFRness, done the blue connector fix (also thanks to Tightwad). New stator. Many connectors and such cleaned up with dielectric spray.

Have run a series of checks with multimeter. Solid readings. Even let the bike heat up, and on the centre stand in neutral, checked the readings up in the VTEC RPM range... solid as a rock.

I do notice a slight flat spot at 3500 and 4500 RPM. Typical on this model, but these don't bother me so much. What bothers me is the much stronger surging above 6800 RPM, not just in the transition range, but at 8500 or 9000 or wherever in the VTEC range if holding steady throttle or making minor imputs to throttle...

I am aware and do agree that the electrical system can be responsible, in reference to bad charging system... when my stator fried the surging was tremendous... way moreso than what I'm noticing now, and this, coupled with the solid multimeter readings, makes me rule out the typical stator, R/R and battery area...

When it comes to the electrical system affecting how the bike runs, I think the VFRness pretty much takes care of the voltage and current capacity/load problems on the 6th Gen bikes. The only other thing is to try a PCIII, as it really helps with the VTEC transition on my bike. Too bad we're on opposite sides of the planet or else I'd let you try my PCIII to see if it makes a difference.

NVR2L8

AuspañolHave the VFRness, done the blue connector fix (also thanks to Tightwad). New stator. Many connectors and such cleaned up with dielectric spray.

Have run a series of checks with multimeter. Solid readings. Even let the bike heat up, and on the centre stand in neutral, checked the readings up in the VTEC RPM range... solid as a rock.

I do notice a slight flat spot at 3500 and 4500 RPM. Typical on this model, but these don't bother me so much. What bothers me is the much stronger surging above 6800 RPM, not just in the transition range, but at 8500 or 9000 or wherever in the VTEC range if holding steady throttle or making minor imputs to throttle...

I am aware and do agree that the electrical system can be responsible, in reference to bad charging system... when my stator fried the surging was tremendous... way moreso than what I'm noticing now, and this, coupled with the solid multimeter readings, makes me rule out the typical stator, R/R and battery area...

When it comes to the electrical system affecting how the bike runs, I think the VFRness pretty much takes care of the voltage and current capacity/load problems on the 6th Gen bikes. The only other thing is to try a PCIII, as it really helps with the VTEC transition on my bike. Too bad we're on opposite sides of the planet or else I'd let you try my PCIII to see if it makes a difference.

Thanks mate!! It's people like your good self that make this site what it is!!

does anyone know if any of the the '07-'08 viffers (sorry: interceptors) have all these electrical and running problems? i want a good bike thats comfortable and has hoot-producing potential, but that wont leave me stranded, or wishing i had a cowboy hat and chaps. i know, i know, im probably the only motorcyclist in the world that wants that, but everybody's different right?

I just started having this surging problem last month on my 2002 model with 51,000 miles. The bike has staintune pipes, K&N, and a DFO installed. I synchronized the starter valves but still the same problem. I also just completed the wiring recall also no change. Surging was at a wide range of RPM's as well as engine operating temperatures. I also had to change the thermostat due to it sticking wide open which made the problem even worse at low temps in the mornings, still no change and I double checked all the vacuum hose connections when removing the throttel body to reach the thermostat. Yah, nice job Honda, maybe next time we can find somewhere better to put the thermostat. I finally double checked my DFO to make sure that it was working and none of the initial setpoints had been changed and everything appeared normal. Following this I adjusted my DFO to add more fuel at the low and mid RPM range and this appears to have solved the surging. I don't know why that has changed but the surging has gone away for now. The surging was to the point where it was dangerous to ride the bike. When will we see a recall from Honda? I completely understand that the bike runs lean without a DFO or Power Commander but the bike still should not surge. I think that I have masked the problem for now but really feel that there is an electrical issue behind this.

Gday Gents (and ladies),

I have an 05 that i bought with 6000km on it. This thing has surges since i had it. Also comes with a nice burning rubber smell when stopped at the lights after its warm.

My surging begins at 80c and anytime after that. It manifests as power coming on and off during steady throttle application on the freeway, almost feels like being buffetted by headwinds.

Other symptoms are when i trafffic and accelerating through the rev range the engine hesitates usually around 4500-5000 rpm. Can be very definite and can also be very subtle.

After reading all posts from various discussions i have drawn a conclusion: This problem can probably be solved quite easily by one solution! Take it to a Tech who you can trust, they will plug in the computer and the bloody bike will probably tell them what the problem is!! I have not done this yet but after receiving a reccomendation finally for a good technician in my area, i am going to give this a crack and will post my results here when the process is complete! I just figure that there are so many people with this issue on these forums but when i talk to a number of workshops, no one has heard of the problem so i figure that all of us here on the forums that are speculating are doing exactly that when there are ways to get the fix (which is likely to be electrical and therefore diagnoseable with a laptop or honda diagnosis program) very easily.

I used to work for Audi, BMW, Porsche and let me tell you, theFIRST thing they all do when a car comes in with a problem like this is open the passenger door, plug in the laptop and let the computer in the car tell them what is wrong. They walk straight to parts, order the sensor/actuator whatever and then replace it. They test drive the car, fixed. The dealership empties your wallet and you drive away without the problem. Im guessing it will be the same on the Viffers due to all the electronic wizardry and i will be very happy if i find out its a 50 buck sensor.

Saves changing throttle stacks, turning the ignition off and on, synching starter valves and doing whatever else to the standard running of the bike that could be removing all that was good about the bike to start with!!

Anyway, not having a go at anyone by saying all that, just saying that it makes sense to me to take it to a tech. Its taken me a bit to drum up the courage to take it to someone again after the first mob butchered my baby but im sure that if they find the problem, it will be worth it in the end!!

Will keep you all posted!!

Let us know how that goes. Good luck.

Alsd

Gday Gents (and ladies),

I have an 05 that i bought with 6000km on it. This thing has surges since i had it. Also comes with a nice burning rubber smell when stopped at the lights after its warm.

My surging begins at 80c and anytime after that. It manifests as power coming on and off during steady throttle application on the freeway, almost feels like being buffetted by headwinds.

Other symptoms are when i trafffic and accelerating through the rev range the engine hesitates usually around 4500-5000 rpm. Can be very definite and can also be very subtle.

After reading all posts from various discussions i have drawn a conclusion: This problem can probably be solved quite easily by one solution! Take it to a Tech who you can trust, they will plug in the computer and the bloody bike will probably tell them what the problem is!! I have not done this yet but after receiving a reccomendation finally for a good technician in my area, i am going to give this a crack and will post my results here when the process is complete! I just figure that there are so many people with this issue on these forums but when i talk to a number of workshops, no one has heard of the problem so i figure that all of us here on the forums that are speculating are doing exactly that when there are ways to get the fix (which is likely to be electrical and therefore diagnoseable with a laptop or honda diagnosis program) very easily.

I used to work for Audi, BMW, Porsche and let me tell you, theFIRST thing they all do when a car comes in with a problem like this is open the passenger door, plug in the laptop and let the computer in the car tell them what is wrong. They walk straight to parts, order the sensor/actuator whatever and then replace it. They test drive the car, fixed. The dealership empties your wallet and you drive away without the problem. Im guessing it will be the same on the Viffers due to all the electronic wizardry and i will be very happy if i find out its a 50 buck sensor.

Saves changing throttle stacks, turning the ignition off and on, synching starter valves and doing whatever else to the standard running of the bike that could be removing all that was good about the bike to start with!!

Anyway, not having a go at anyone by saying all that, just saying that it makes sense to me to take it to a tech. Its taken me a bit to drum up the courage to take it to someone again after the first mob butchered my baby but im sure that if they find the problem, it will be worth it in the end!!

Will keep you all posted!!

Dandizzle

does anyone know if any of the the '07-'08 viffers (sorry: interceptors) have all these electrical and running problems? i want a good bike thats comfortable and has hoot-producing potential, but that wont leave me stranded, or wishing i had a cowboy hat and chaps. i know, i know, im probably the only motorcyclist in the world that wants that, but everybody's different right?

06 through 2010 have had zero recalls, and everything has been getting retrofitted to this level.

I have 76,000 mile on my 06 (no valve check), and the first real part failure was a stator at 56,000 mile. Theres no bike your going to buy with better longevity IMO, I rely on my bike to be trouble free. NOw as with any other bike, its all in your early prepping that bears fruit down the road

you should only be so lucky with any other bike

But if you put a set of heli bars and a good seat, VFR is a luxury liner

Ok All,

The shop has just called.

No problem found. Plugs changed, fuel drained and then test ridden. Problem appears to be gone they say.

My previous words (fantasy) about them plugging in a laptop and being told what the problem is appears to have been a pipe dream on my behalf. I am prepared to eat all of my own words and take any ribbing from those willing to give it :)

I'll have to put some k's on the thing and see if i agree with their outcome!!

Was liberated of $285 for the privilledge too!!

Al.

EPA settings has 1/4 throttle lean, it shows up as a mild surge in some rpm areas, we are talking mild surge not bucking or anything. Take all the slack out of your throttle cable, that will aide cause of the wrist position will change.

If running any modifications , like airfilter or exhaust, expect more issues, without a properly set up PCommander. The bike is too lean stock below half throttle to absorb any modifications that would lean it out further.

Keep in mind US fuel map is changing and not to our benefit, this will also create issue.

spud786

EPA settings has 1/4 throttle lean, it shows up as a mild surge in some rpm areas, we are talking mild surge not bucking or anything. Take all the slack out of your throttle cable, that will aide cause of the wrist position will change.

If running any modifications , like airfilter or exhaust, expect more issues, without a properly set up PCommander. The bike is too lean stock below half throttle to absorb any modifications that would lean it out further.

Keep in mind US fuel map is changing and not to our benefit, this will also create issue.

Thanks Spud,

She's Stock as a rock. WIll have a look at the throttle cable. Sometimes it can buck about but thats usually in traffic and when its hot. On the freeway its uslually a lack of power being applied when applying throttle.

Prick of a problem. Considering my options should this not be sorted when i get it back.

Just make sure the throttle valve fully closes lock to lock on the bars( so rpm doesnt raise with turning the bars) . but somwhere between zero and 2mm play. Stock , they normally come with about 5mm or more of play. it will aide in the first 1/4 throttle use, you might also find acheiving full throttle easier.

But even new and perfect condition there are spots in the rpm range that will generate some mild surge, if in that 1/4 throttle range.

Also possible your fuel injectors ar alittle clogged, might try some fi cleaner, strong enough a metal can is needed.

Alsd,

I have the same problem on my 05, PITA :fing02: The surge/ hesitation @ 5000 rpm's is annoying as hell! :biggrin:

I just added some FI cleaner the week, hoping this will sort it out. Will also post back with any results. lol :comp13:

Alsd

My previous words (fantasy) about them plugging in a laptop and being told what the problem is appears to have been a pipe dream on my behalf. I am prepared to eat all of my own words and take any ribbing from those willing to give it :)

Sorry mate, but the PGM-FI control unit on the VFR just isn't that smart. Only vehicles with the newer OBD-II (Onboard Vehicle Diagnostics) can guarantee such levels of diagnostic capability. Even then, if the problem is not considered an error it won't show up.

Having said that, a modern car ECU such as the Blackwood unit used on most Fords has very strong diagnostic capability, mainly due to the O2 sensor. They know what an engine which has no problems should show with regards to the O2 readings and such. In addition, nearly all car ECU systems use a mass air flow sensor for measuring air and therefore appropriate fuelling. Nearly all bikes - with possibly the exception of Ducati - use Manifold Absolute Pressure (MAP) sensors and are essentially an open-loop system (that is, they can't learn or adjust to circumstances outside of their preprogrammed maps).

A car with a mass airflow sensor can be practically blueprinted or fitted with hot cams without a re-tune, because these systems measure the airflow and apply the right amount of fuel in accordance, and then take readings from the O2 sensor to make sure they're getting it right.

To put it mildly, the VFR O2 sensors are next to useless. They only monitor fuel mixture at a very small window of operation (cruising rpms, less than 25% throttle) and as far as I know, they forget the data as soon as you turn the bike off. It's just not a true closed-loop system, unlike a modern car. The best way to make a 6th-generation VFR run well is to bung on some O2 sensor eliminators, a Powercommander (III or V - either will work), and a custom tune. I just had mine tuned and I told them I didn't give a toss about power, I just wanted smooth throttle response at cruise. And that's what they focused on - the results are pretty darned good too.

Hey Guys,

Well have done 200ks on her since the service and i have to say that its a MASSIVE improvement. The flat spot at 2000-3000 rpm is gone, the hesitations at around 4000-5000 have pretty much gone but there is a hint of it stil. Overall though, the improvement is awesome. I am back in love with her and i now feel that i can see why there is so much love for this machine. Was about to bin the thing a while ago!!

Kal, The power commander and sensors etc, was thisa a recent development? I know you have been struggling for a while and im curious as to how recent the work was?

Thanks for all the replies gents!!

Al.

Has anybody with an ABS model every hook up an electrical reader to the ABS to see what kind of power it pulls when in use/not in use?

NVR2L8

AuspañolHave the VFRness, done the blue connector fix (also thanks to Tightwad). New stator. Many connectors and such cleaned up with dielectric spray.

Have run a series of checks with multimeter. Solid readings. Even let the bike heat up, and on the centre stand in neutral, checked the readings up in the VTEC RPM range... solid as a rock.

I do notice a slight flat spot at 3500 and 4500 RPM. Typical on this model, but these don't bother me so much. What bothers me is the much stronger surging above 6800 RPM, not just in the transition range, but at 8500 or 9000 or wherever in the VTEC range if holding steady throttle or making minor imputs to throttle...

I am aware and do agree that the electrical system can be responsible, in reference to bad charging system... when my stator fried the surging was tremendous... way moreso than what I'm noticing now, and this, coupled with the solid multimeter readings, makes me rule out the typical stator, R/R and battery area...

When it comes to the electrical system affecting how the bike runs, I think the VFRness pretty much takes care of the voltage and current capacity/load problems on the 6th Gen bikes. The only other thing is to try a PCIII, as it really helps with the VTEC transition on my bike. Too bad we're on opposite sides of the planet or else I'd let you try my PCIII to see if it makes a difference.

NVR2L8

I've been meaning to post my recent findings...

If you've read thru the entire thread where I discussed some of the mods I have done to my bike, as well as some of the things I did that had an affect as I tried to eliminate the hot running surging, one of the first things that stood out as a partial fix were the velocity stacks.

The arrangement of the velocity stacks in this configuration, Left Front: Short, Right Front: Tall, Left Rear: Tall, and Right Rear: Short, made a definite difference. I commute to work on my VFR every day, so I believe I ride it enough to be able to tell when something makes it run better or worse. The velocity stacks in the above arrangement seemed to help but didnt totally eliminate the hot surging.

I had already done most of the electrical mods, such as the 30-amp fuse fix, left-side blue connector ground wire, and so on, but since my bike is fairly new and the wiring seems to be okay so far, I thought of these mods/upgrades as preventive measures since none of them affected the surging. What I didnt realize is that my particular surging problem was related to the electrical system.

About 3-4 months ago I noticed that my barely 2-year-old battery was starting to act up. In the summer mornings it seemed as though the engine was becoming harder to start, and when I hit the starter button it took several revolutions until the engine started. Work with me on the sound effects here, but it was like woo woo, woo woo, woo woo, woo woo, vroom!!! Slow tickover until it finally gone caught and started. I also had an instance where I stopped at a traffic light, and the idle dropped to about 500 rpms for about 10 secs before it finally came back up. I finally decided to just replace the battery when the bike barely started after the third of several errands I had run during my work lunch break.

I went with an FTZ-14S from motorcyclebatteries.com, which is the same size as the stock battery, but has a few more cold cranking amps. The first time I hit the starter button after installing it the engine fired up with a woo woo, vroom!!!, so I know my slow starting was due to the battery. Maybe my stock battery is somehow defective and just doesnt hold a charge correctly...?

The next morning when I rode to work I didnt even think about the new battery, until I noticed the engine seemed to be running a lot smoother. During my 40 minute commute I didnt notice any running surging whatsoever, although I really didnt believe the battery could have been the source of the problem. So, for the next week I decided to really focus on how the bike ran in really hot temperatures. Well, I installed the new battery a little over two weeks ago, and in my particular case I think that was the problem. Weve had some pretty hot temps here in SoCal for a while now, and there have been only a few times where Ive noticed only a very slight surge or a slight on/off throttle dead spot. But its nothing compared to how it ran beforeits a night and day difference. In fact, I am amazed at how smooth it runs now. I can run in 1st gear at 5-6K, at engine temps well over 200F, and it doesnt surge at all. Nada...

A few days after installing the battery I decided I had better also do the monitor wire fix, as although my voltage below the high level per the service manual at about 15.1 15.2 volts, I was worried that maybe the battery had gotten overcharged and that is what made it fail so quickly. After the wiring fix my voltage is now steady at 14.2 14.3 volts. I really dont think the running voltage was the problem, as the engine definitely ran better after the new battery was installed, but the same after the monitor wire fix.

SoI think my hot surging issue was electrically related, but Im not sure how. The only thing I can figure is that the overall electrical system would become degraded after the bike fully warmed up, and somehow the battery was part of the equation, although I don't see how the battery could change characteristics depending on engine temperature. Anyway, my advice is that if you experience a similar problem, do yourself a favor and perform all of the wiring fixes/upgrades, but first have the battery checked as a potential source.

Well I realise this post is quite old but I did come accross this quote in the service maual; "The volume of fuel injected is compensated when the feeding voltage of the battery is low." It was in the technical features section regarding the ECM. Whether that would be only at start or all the time i can't say, but it would appear that replacing the battery did help and this may have been part of the reason why. Before anyone goes there, yes when running the R/R should have a fairly stable voltage but electrons being what they are, you never know.

I've just posted You see but you do not observe (aimed at myself). After three months of anguish, I've finally fixed my surging problem - it was staring me in the face.

Not saying this is your problem but worth a look for sure.

Ciao

Some EFI systems will keep the injectors open longer when the battery is low. Rationale is the lower voltage will result in the injector solenoid operating more slowly than normal, so leaving it open longer will compensate for the extra time required to open.

It could have been overcompensating and running the engine rich,, resulting in your surging at the low end. Maybe.

Surging sucks. :o(

I have a similar surging issue. One of the questions I have was answered. Mine is an 06. When it is cold it starts and idles very well. When it gets to operating temperature it starts surging. If is was a car I would suspect the Throttle Position Sensor. That is the question that was answered. Yes, the bike does have one. Next question, Where is it? How do I get to it to clean it and see if that is my problem. I did take it to a local Dealership. They were no help at all. There are only 3 VFR's, that I know of, in the Sate of Utah. Any help is greatly appreciated.

TPS is circled in red

[image: TPSSensor.jpg]

Hi everyone,

2007 RWB VFR800, 33,000 miles, completely stock, no modifications

I will add my experience to this thread. I just tuned the starter jets on the four throttle bodies this past weekend. The bike was surging terribly, idle went from

@ 1,500 - 1,000.. I bought the Carbtune equipment, printed the manual and dug into this problem. After preparing everything and finally getting the Carbtune PRO tool hooked up, I started the bike. Well, looking at the Carbtune PRO tool, it was an OMG moment. No wonder this bike doesn't run right. Let's just say they were not in alignment. After about 30 or so minutes, finally got all throttle bodies to within .5 cmHG of each other. (Had fan blowing on engine ) The bike idles smoothly and twisting the throttle is very responsive. I am thrilled..

🙂

I also noticed that my bike had two short stacks up front and two long stacks in the rear. (Bought new, this is how it came from factory). Others had commented that this was not correct and indeed the manual shows a short, long up front and a long, short in rear. I changed them accordingly. I am thinking the worker doing the assembly just put short in front and long in rear.

Thanks for all previous comments and help,

Bill Mersch aka MisterBill

If you look at the floor of the airbox, the rear is deeper, thats why the long stacks go in the rear and short in the front. so they are the same height installed.

3 hours ago, spud786

If you look at the floor of the airbox, the rear is deeper, thats why the long stacks go in the rear and short in the front. so they are the same height installed.

Hi spud786.

Sorry, don't agree with you on this one. It's a bit more complex than that.

The stacks should be staggered as per the Service Manual. As to how much of benefit having them staggered makes could be debatable, however, Honda has done it this way for a reason.