iNERtIA

im having some with my car, it would go full rich for a few seconds before going full lean whenever i decelerate hard and blow smoke from the exhaust, it does the same thing when i when let go of the throttle when cruising before going to full lean on decelerate. im running on chrome.
once i a while i have idle hunting issues as well, and during cold start-up, it only idles around 1000rpm. if thats connected at all.

TIA


Modified by iNERtIA at 12:55 AM 4/22/2007

iNERtIA

bump for an answer.

supabang

what color is the smoke?

iNERtIA

sometimes blue. i knw its oil. im more concered why it goes full rich.

NJIN BUILDR

It may just be that your wide band is going out of range and is just showing rich.Hondas shut off the injectors below a certain tps so it isn't really going rich.I notice mine will read 19.99 and sometimes 9.9 other times.

HiProfile

Well your first issue would be your driving style. Decelerating from redline to idle (or even for a few thousand rpm high up) puts the most stress on your rods. Its also stressful on your turbo, since you still have 50psi+ pushing at your turbo's restrictor while you have zero pressure pushing on the other side of the compressor seal.

Its probably a tuning issue, though. The only good way to tune part-throttle is via street tuning, since high-vacuum areas on the maps with large injectors present very short duty cycles. Small changes here show as large afr swings. The last column in the map will usually add just enough fuel to keep combustion active, and a slight error in setting the maps up will add a lot more fuel than needed. You'd really have to look at your datalogs to see if, upon decel, it stays in the last column the whole time or if it changes from rich to lean when it switches to non-vtec maps (if you have vtec).

If you mean it goes rich for a fraction of a second, then lean, it might be the medium-load cells on the map that are way too rich. Those between 18 to 5 in/Hg aren't easy to tune, as you usually just barely touch them upon decel. One reason turbo cars shoot flames upon decel is those cells being too rich (the other is a non-recirc. bov on a MAF car not tuned for it).

Other than that, you haven't given us much to make suggestions from.

iNERtIA

^thanks. one example is.. well during hard deceleration, say after finishing the run on 1/4mile. it would stay full rich for several seconds b4 going full lean. black smoke would shoot out of my exhaust i believe.

one more thing is while cruising and i let go of the throttle it would bounce to full rich for a second then go to lean.

i hope u know what i mean, sorry im still new with these tuning stuff.

thanks!

93supercoupe

push the clutch in on decel.

HiProfile

Sounds like your fuel maps should be looked at again, particularly the high-rpm, low-load cells on the vtec map, and the semi-low load cells on both maps.

A bit of advice is to push your clutch in any time you let off the motor, within reason, or decel slower when possible. Engine braking is for dump trucks, not hondas.

iNERtIA

oh yeah definitely, the only time i decel hard is when its needed, i'd rather change brake pads more often than break my motor.