I was running lean between 5000 to 6000 rpm just after the VTEC kick in, so my tuner added 5 point of fuel on the Hondata. I can definitely feel the gain in that rpm range (both partial and full throttle), but now I am having some hesitation problem between 4000-5000rpm in partial throttle (around 10-20% throttle). BTW, the hesitation only occurs during partial throttle, in full throttle, the car pull very smooth.

When the hesitation happen, I can hear "pop pop pop" sound from the exhaust, am I running too rich?

Did the fuel I added between 5-6000rpm have anything to do with the hesitation?

Should I take out a bit of fuel at 5000rpm or should I add more fuel between 4-5000rpm?

Any help would be nice, thanks!!

 

you should get a new tuner or get advice from hondata, not here.

 

Fuel added between 5-6000 rpm should not affect the fuel map between 4-5000 rpm. Double check your ignition system. If all is well, try adding fuel on the non-VTEC map between 4-5000 rpm. If the problem gets worse, try removing a little fuel from the same part of the map. You also might want to IM C_A_T on this board to see if he has any helpful input.

 

I don't think it is the ignition, because the power was smooth until the tuner added fuel to 5-6000rpm because it was running lean.

 

Were you tuning on a dyno?

 

Was the car tuned on a load type dyno or on the street? If your tuner didn't do part throttle tuning with a wideband, I'd suggest that the mixtures are off, most likely lean to cause the symptoms you describe.

C_A_T

 

The partial throttle was tuned on the dynopack with a wideband to get the mixture to near 14.7. I didn't have the problem until I added fuel to 5-6000rpm to take out a "flat spot" under full throttle. After I added the fuel, the flat spot between 5-6000rpm under full throttle was gone, but now I have hesitation between 4-5000rpm in partial throttle.

 

Sounds like something else was inadvertently changed during the correction for the flat spot then. I'm sure it was just an accident. Take it back and have them clean it up for you.

C_A_T

 

Hummm, I don't think anything was changed by accident, since I was there when they do the changes. Will making a big changes in 5-6000rpm full throttle have any affect on 4-5000 rpm partial throttle?

 

Shouldn't have any effect at all. You're talking about two (or more) different columns and two different rows on the fuel maps. Either something is broken on your car or they changed a part of the map they shouldn't have.

Did you actually watch the screen while they altered the Hondata maps?

C_A_T

 

Went back to the tuner tonight, put back my old program with a bit of modification, run a lot smoother now. Didn't have time to play around with the hesitation map, but one thing I noticed was that there was a big jump in fuel at 5000 rpm from one cell to the cell to the right of it (like 300 in the fuel). And I compared it with my old program, and it didn't have any big jump in the fuel map anywhere within the same rpm and different throttle position. May be that's the problem?