idle problems
 

When I start my car it will idle fine while cold. After it warms up the idle will start jumping from 900 to 750, and heavy black smoke will come from the exhaust.

Does it make a popping noise too? What mods do you have, when did this start? Do you have any fuel computer or PFC? How does it drive, accelerate, and decelerate? As you've said, it sounds like it starts running rich when warmed up. Could be a bad temp / thermosensor?. Give us more info. about your car and the above, maybe we can help better.

Map sensor hose.....TPS......first places to check......

Did u go WOT on it before those symptoms?

Idle Problems
 

Sorry I didn't get back earlier. I know ishould have put more info but had no time.

My mods are single rebuilt motor 3k miles, port polish, single turbo, pfc w/comander no datalogic, hks sparkplug 9&10 new, 1300 & 550 injectors, eliminated solenoids, front mount ic, 3mm apex seals, running 15 lbs boost.

Symptom started started one day when I drove car to restaurant. I used to have trouble starting car, I would have to hold accelerator until warmed up. That day the car started and idled on its own. When I started driving black smoke poured out the exhaust, and bad excelleration. The more I drove the worse it got. When I returned home the idle was jumping and it was spitting up. Afraid of Blown motor, I let the car sit for the winter. I started playing with it again slowly in spring.

Things I have checked

compression test- ok
Idle speed control-ok
water thermo sensor- replaced
fuel thermosensor- ok
no egr
no charcoal canister
no purge control
IC hoses and couplers
vacuum hoses
coils- ok
spark plugs and spark-ok

Questions
Manual says:
Pressure regulator control- system cancels the vacuum applied to the pressure regulator and increases the fuel pressure during hot engine start up and for a period immediatley following engine start up. This improves hot starting as well as smooth idle. Then says "approximately one minute during and after engine startup."

If its only for one minute could it really control idle?

What do you mean by popping?

Really busy but and hard to reply but all info is greatly appreciated
THANK YOU

Idle Problems
 

stupid typos
single turbo not single engine rebuild
and there are others