Quote:
Originally Posted by ChevyTech
Yes; that rules out the booster if it still runs to fast with your thumb plugging the hose.
When checking for leaks make sure you check the base gasket under the TBI. As Mechanic77 stated it is a common problem.
You said it eventually slows down, so the IAC could be getting bad a sticking.
Usually the IAC does not go bad electrically, but it is common for them to stick and stop moving.
The IAC is a stepper motor and uses short pulses of electricity on the wires to move its position.
If the IAC sticks as does not move as it should for each pulse, the IAC count will get off because the computer does not know the actual position of the IAC, but the ECM tracks the commands it has sent to the IAC and assumes it has moved every time it has been sent a pulse.
To clean the IAC, you should remove it, and use a wet rag to wipe the tip of the plunger, while holding it with the plunger pointing DOWN. Be careful, the IAC will break easily. It is aluminum. Clean the passages in the TBI unit while you have the IAC removed.
I do not suggest unscrewing the pintle (plunger). If you don’t get in back in far enough, the IAC can get damaged if the “pintle” (plunger) bottoms out in the TBI, when you screw the IAC back in.
You can look down from the top and see the IAC plunger if it is in the normal idle position.
Glad you are feeling better.
|
Thanks, ya me too that was bad
Well i rebuilt the engine about 10k ago and put a complete new gasket kit in, should i pull the TBI and just check? I wouldnt think it would be the gasket but ya never know..
Just drove it to the hardware store and when i come up to a light and stop it idles about 900 (if i were to put it in park it idles up around 1500) but slowly starts to idle down to around 300 (ish) about 30 seconds after i stop.
Ok i will take it out and clean it up and get back to you with what i have found.