Running Rich And Surging

I just did a 3400 mile trip to Sturgis from San Antonio,TX. The bike ran great the first day but when I got into the Pueblo, Co. It wouldn't idle and no power until over 5500 rpm. We ran over 90 mph in Wyoming for about 50 miles and it ran ok but rich. When I got to Sturgis I put in a new set of plugs thinking I fouled the old ones with a tank of bad gas. It would idle and run good until it warmed up. I drove it this way all week and then home. I only averaged about 150 miles per tank and ran we between 80 and 90 all the way home. It is still running rich and it surges when I go down the highway. Still runs sluggish until I get to about 5500 rpm and then surges about every 5 seconds. I am up for suggestions. It now has 12000 miles on it. I bought it last year with 600. It has Leo Vince exhaust and a k&n filter that has been on it all year, never had a problem before. I changed the oil and filter before I left. I also checked the filter and it is clean.

[image: View Post]sapd1098, on Aug 10 2009, 01:00 PM, said:

I just did a 3400 mile trip to Sturgis from San Antonio,TX. The bike ran great the first day but when I got into the Pueblo, Co. It wouldn't idle and no power until over 5500 rpm. We ran over 90 mph in Wyoming for about 50 miles and it ran ok but rich. When I got to Sturgis I put in a new set of plugs thinking I fouled the old ones with a tank of bad gas. It would idle and run good until it warmed up. I drove it this way all week and then home. I only averaged about 150 miles per tank and ran we between 80 and 90 all the way home. It is still running rich and it surges when I go down the highway. Still runs sluggish until I get to about 5500 rpm and then surges about every 5 seconds. I am up for suggestions. It now has 12000 miles on it. I bought it last year with 600. It has Leo Vince exhaust and a k&n filter that has been on it all year, never had a problem before. I changed the oil and filter before I left. I also checked the filter and it is clean.

Do you have a Power Commander? Not sure about the altitudes involved, but do you know approximately how much the altitude change was? Though the fact that it's still running bad leads me to think that would be unrelated. Does it still run better when cold?

[image: View Post]Ryanme17, on Aug 10 2009, 11:21 AM, said:

[image: View Post]sapd1098, on Aug 10 2009, 01:00 PM, said:

I just did a 3400 mile trip to Sturgis from San Antonio,TX. The bike ran great the first day but when I got into the Pueblo, Co. It wouldn't idle and no power until over 5500 rpm. We ran over 90 mph in Wyoming for about 50 miles and it ran ok but rich. When I got to Sturgis I put in a new set of plugs thinking I fouled the old ones with a tank of bad gas. It would idle and run good until it warmed up. I drove it this way all week and then home. I only averaged about 150 miles per tank and ran we between 80 and 90 all the way home. It is still running rich and it surges when I go down the highway. Still runs sluggish until I get to about 5500 rpm and then surges about every 5 seconds. I am up for suggestions. It now has 12000 miles on it. I bought it last year with 600. It has Leo Vince exhaust and a k&n filter that has been on it all year, never had a problem before. I changed the oil and filter before I left. I also checked the filter and it is clean.

Do you have a Power Commander? Not sure about the altitudes involved, but do you know approximately how much the altitude change was? Though the fact that it's still running bad leads me to think that would be unrelated. Does it still run better when cold?


no power commander... i thought it was the altitudes also but just went outside and when a rev it up black smoke comes out the exhaust. Running rich it seems

What did the plugs look like when you pulled them? Have you checked for error codes?

Action

[image: View Post]sapd1098, on Aug 10 2009, 04:25 PM, said:

no power commander... i thought it was the altitudes also but just went outside and when a rev it up black smoke comes out the exhaust. Running rich it seems

One of the sensors checks air density and would've adjusted accordingly. The only way that would've still affected your bike now is if your sensor was off and you fouled your plugs, not likely... So that's mostly ruled out...

What did the plugs look like when they came off?

Will fouled plugs cause a rich condition or are they more likely caused by a rich condition?

two of them looked fouled and i belive they came out of the right side.. there was also a wet look on the rear of the air bax next to the throttle bodies.

[image: View Post]sapd1098, on Aug 10 2009, 05:35 PM, said:

two of them looked fouled and i belive they came out of the right side.. there was also a wet look on the rear of the air bax next to the throttle bodies.


If you overfill your engine with oil, the overflow will start to come up into the airbox.

wasnt oil it was fuel

Sounds like some sensor went bad on one bank of cylinders! Don't think an 02 sensor would cause this unless it was shorting or something weird?

Do check for ECU codes, if there's one there it will most likely tell you the issue! :blush:
If you don't have a Honda Shop Manual you can download one here!
http://www.vfrdiscus...p...&showfile=9

I took the bike apart today and I bypassed to read the codes and it showed no code errors, looking to see if I can test the fuel pressure valve now

installed the new fuel pressure regulator and that took care of the problem, thanks for all the help.

[image: View Post]sapd1098, on Aug 11 2009, 02:13 PM, said:

I took the bike apart today and I bypassed to read the codes and it showed no code errors, looking to see if I can test the fuel pressure valve now
I have the same symptom as you.. Since you did replacement about your fuel pressure valve, the problem is still resolved ?