As opposed to daily street driving.

My car runs excellent around town. Smooth, great throttle response, all-in-all it seems the closed-loop function is tops.

Couple things about the vehicle:

• 383 w' LT4 heads/intake, and forged internals, ATI twin-intercooled P1SC procharger with ~10psi@6000 . Mild cam, good heads, 42# injectors, exhaust, etc. Puts down 400+
• I have LT1_Edit and have edited my PCM4LESS file to accomodate my preferences and changes.

Problem: During hard acceleration it seems to be overly rich, bellowing dark unburnt fuel.

It seems that this is mostly due to my programming changes, where I take timing down to 25* from 30* in progressive stages up to 7000 RPM for 100KPA. I also move PE to 99* for all 100KPA above 4000 RPM.

For fuel, I have plenty available, but I think I overcompensate by moving my Fuel Enrichment through stages from 5% to 15% as RPM climbs. I want to pull fuel out, but unsure about what's right...

I intentionally add fuel due to the boost and don't want detonation, but I think I've just been putting too much in.


(I know...dyno tune...) I can't right now due to $$ and a weak clutch.

 

What year is your car?

 

96 w' OBDII

 

I use Tunercat on an OBD1 car. I will check tonight to see which tables may help you.

Also, if you have too much fuel wash you could be diluting your oil and washing oil off your cylinder walls. That can also be very damaging.

The next best way to check if you can't afford a dyno is to get a portable 5V wideband O2. Cheap ones are cheap. Get one that recalibrates the O2