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98 Vfr Trouble Accelerating

10 posts Started 3 Mar 2015 Last recovered post 3 Mar 2015 Wayback Machine snapshot 6 Mar 2015

#1
Hello, I am new to the site and a new rider. (1year) bought the bike used worked great for about six months. Bike has definitely seen better days. Bike was working great, one day while out I went to start the bike and no luck. Took the bike in had the starter replaced got it back they said it was running great, rode it home (10 minutes). Took it out the next day and rode about 10 minutes and parked. Come back start the bike and Roll the throttle, nothing. let it sit for 30 minutes while waiting for a ride tried starting it just to check, and it would move just not very quickly.clearly something still wrong but I got it home. It seems to accelerate but loses power as I accelerate, switch gears it catches but it's missing all the power. If I give it 25% it gives me 5. Unfortunately I was in the middle of moving to another city and didn't get it back to the shop. They also left two bolts off my tank but that's another story. Any thoughts or suggestions from some educated riders? rode in the neighbor hood today today just to see I got moving but something is definitely wrong I accelerate and it just drops off with sudden acceleration.
Correction* the bike does not lose power it does nott accelerate like it should.
#2

Is there a "limp mode" with the EFI system on the 98? It might be what's causing the non-availbility of full power from your bike's motor?


#3

You should be able to download the service manual for your model here (free).  It's a large file, so depending upon your connection it might take a while.

http://www.vfrdiscus...-servicemanual/

If you go to section 5, page 3 (fuel system), there is a troubleshooting table, and starting on page 5-6 how to evaluate any trouble codes from the ECU.  It could be as simple a something like water or condensation in the fuel.  A video (and of course a few pics) can be helpful. 


#4
Thank you for the direction! I did notice today that when I pulled my key out of the gas tank it was wet with gas. Maybe water has seeped through. I will head to the manual!
#5

The key (?!?) was wet with gas?  Strange, but ATM I can't think of how that may be related to a loss of power. 

It ran pretty normal on the ride home from the starter repair?

Is your red FI light on all the time?  Does it turn on momentarily during startup?  It should.  IF it doesn't light up during startup, the bulb is burned out, and a kind of pain to replace.  Let me know if it is working and we can proceed from there.

Otherwise, was the bike stored for any length of time between its normal operation and when it was running bad?  You may want to check the airbox and make sure some mice didn't make their nest inside.


#6
So unfortunately included in the "this bike has seen better days" is the fact the the bike is stripped. Nothing. No lights speedometer odometer fairings mirrors. Bare bones. There was no storage period in between the starter replacement and the issue . It was a brand new issue directly after taking it to get the starter replaced. And now that I've moved I doubt the shop would believe me. It's just so strange when the bike is cold sometimes it will accelerate but more than five minutes and I'd be stuck rolling the throttle going no where.
I was very surprised by the key being wet as well. I'd love to keep the conversation open. That being said I will be looking at the manual now that I've downloaded it.
Also I want to make sure we are clear the bike is always running it doesn't lose electrical power just the ability to move..
#7

Ok, stripped we can work with, just makes it easier to get to stuff.  There is a big blue and big grey connector that used to plug into the dashboard, are they still there?


#8

Thank you for the direction! I did notice today that when I pulled my key out of the gas tank it was wet with gas. Maybe water has seeped through. I will head to the manual!

If you have water in the fuel tank it's more likely either from moisture in the air condensing on the inside walls of the tank (like a glass that gets wet on the outside when it's filled with ice water).  I keep my tank full when it's not being ridden to prevent it.  Another source is from phase separation due to the ethanol in fuel available today.  Here's an article that talks about it - it can happen in as little as 30 days.  It's worse in humid climates.   Both these issues crop up when a bike's been sitting for an extended period of time - particularly outside. 

http://fuelschool.bl...ol-blended.html

Water is just one possibility - it may well not be your problem.  It's easy to eliminate though - just prop the tank up and siphon it all out.  Refill with fresh fuel and see what happens.  If the problem persists, continue to trouble shoot.  Best of luck with it. 


#9
Yes big blue bug gray. All the wiring is attached
Big*
Big*
Thank you cogswell
I don't know if this matters but my high beam does not work either but that could be a few things unrelated.
#10

So first you are going to need a 12v test light, this is going to be your check engine light, you can usually find them at local hardware stores, harbor freight, radio shack...  Just make sure it is 12v dc.

[image: test light]
test light

$5 Harbor Freight Model

1.  With the bike off, clip the lead of the test light to the positive battery terminal.  Make sure the metal clip part of the lead doesn't touch the frame and the terminal at the same time, bad things will happen™

2.  You should test your lamp to make sure it works, touch the metal tip of the screwdriver thing to the frame or negative battery terminal.  If the light doesn't go on, return it and get another.

3.  Find the big GREY plug that used to go to the dashboard.  Identify the pin belonging to the White/Blue Stripe wire.

4.  With a helper or some way to hold everything together, place the tip of the test probe only on the pin you just found in step 3.

5.  Turn on the key and start the bike.

The FI light should light up briefly during startup and be off when the bike is running.  I can't remember exactly when and how long the light comes on, but my bike is winterized right now so I can't go find out.  Once the bike is idling, the light should be out.  If the light remains on or flashes when idling, this is good and bad.  Means something isn't working, but we now have some way of finding out without blindly doing maintenance or replacing parts.  If the light stays on or flashes, you may want to rig up a temporary small automotive light so we can get "codes" from the ecu without having to screw with the test light.  Go do this first though and let us know what happens.

Best of luck


End of thread · 10 posts recovered Wayback Machine snapshot 6 Mar 2015