Cascade Crew

Xophertony

so the only "problem" my 1986 firebird still has running wise is this issue i have had for a while. it was dieing whenever i let the RPMs come down to idle. i thought it was an IAC. when i had my intake off i cleaned the TB IAC passages, and cleaned the IAC. the problem was almost gone. almost. now instead of dieing every other time i stopped it would die once or twice a trip. i went ahead and replaced the IAC with a new one. the problem is still present. it dies when the engine is coming down from cruise back to idle. but it only happens every once in a while. like once or twice in a twenty minute in town trip.

does anyone know what this could be?
the IAC is brand new.
the TPS is new about a year ago.
the MAF is new about 7 months ago.
cap and rotor are new about three weeks ago (broke cap when i had intake off)

can anyone help me? it is quite emberassing when i come to a stop and then have to re-start my car. Sad

Quasi-Traction · Posted: Sat Aug 19, 2006 2:27 pm Post subject:

Any holes or fractures in vaccum hoses? One vaccum hose routed improperly perhaps?

Manifold leak of some kind?

My fairlane does it too when its cold. I blame that mostly on the crappy choke on it though.

Xophertony · Posted: Sat Aug 19, 2006 2:48 pm Post subject:

well, i was quite carefull in preparing my gasket surfaces, and i am almost certain i routed my vaccume hoses corrctly, but i'll take another look the next time i have the hood up. while i had it all apart i inspected all the lines and those not in good shape were replaced with extra hose i had on hand.

maniflod leak.... that would allow unmetered air into the intake, (or in worst case, oil and water into places they should not be) i see no evidence of oil or water leaks in the manifold, but air.... would that cause it to die randomly like it is doing?

Danked · Posted: Sat Aug 19, 2006 10:31 pm Post subject:

i dont see why it wouldnt, when too much air is sucked into the engine without a sufficient amount of gas to compensate, it runs funny, it would explain alot. sorry if this means nothing, im just trying to help

aaron_sK · Posted: Sat Aug 19, 2006 10:58 pm Post subject:

Have you run a vac. gauge on it yet?

Xophertony · Posted: Sun Aug 20, 2006 11:46 am Post subject:

no i have not. my dad has one though, so i will get around to it.

chevymad · Posted: Sun Aug 20, 2006 12:18 pm Post subject:

Could be a sticking EGR valve too. Disconnect it and see if the problem continues.

Xophertony · Posted: Sun Aug 20, 2006 9:03 pm Post subject:

that makes ALOT of sense as it always happens when i am coming down from cruise. and that is when the EGR is active. good thinking brandon, i'll bet that is what it is.

aaron_sK · Posted: Sun Aug 20, 2006 9:11 pm Post subject:

Does it happen when the car is first warming up?

Xophertony · Posted: Sun Aug 20, 2006 11:12 pm Post subject:

no. only once warm. which further points to EGR as a manifold vaccume leak would be prety undiscriminitory, as would a leak in the rest of the vaccume system. hmmm.. might be time to remove my EGR. (yay, a cleaner engine bay, and less carbon in my TB, booo not as good of gas mialage.)

aaron_sK · Posted: Mon Aug 21, 2006 10:23 am Post subject:

Yup. My IROC was doing the same thing before I parked it. Which reminds me, I need to call Scott about that valve.