High Idle Problem

[chadz34]

Well, after the car is warmed up, when I start it, it idles at 1,500 rpm and slowly and I mean SLOWLY comes down. I could understand first start of the day, but it shouldn't high idle when it's FULLY warmed up. Also, when I put it in PARK it revs up to 1,500 again, then slowly comes down....Is this the little plunger thing in the throttle body? Could it be stuck? The CHECK ENGINE light is on too. I fixed the other idle problem but now I have this one. BTW this is a 96' Lumina DOHC. I was talking to Luke and he thinks TPS, I hope so cause it's the cheapest thing to do with idling.

 

[chadz34]

BIZZUMP.

[jdcutty]

TPS, IAC, or cracked vac lines that leak when warm.

[slick]

Vacuum lines. Check them.

 

Wait, didn't I tell you to do this the last three times you posted about high idle problems?

[SigEpCutlass]

Make sure the TB cables are properly adjusted. Other than that, check your vac lines like we've suggested for some of the other problems you've posted.

[White93z34]

if the check engine light is on take it to a auto parts store that checks codes for free and tell us the trouble codes, that will probably be a big help in diagnosing that problem.

 

did you ever clean/replace your IAC? i had one go bad a year or 2 back that would make my car idle at around 1500

[SigEpCutlass]

btw have you done the idle relearn procedure?

http://www.w-body.com/forum/index.php/topic,31176.0.html

[chadz34]

Vacuum lines. Check them.

 

Wait, didn't I tell you to do this the last three times you posted about high idle problems?

I had my vacuum leak fixed at the GM dealership. I'll take it back up there, I put my CHECK ENGINE light off by disconnecting the battery and it hasn't come back on yet.

[White93z34]

well that isan't helping you, wait for it to come on again, and find out WHY its on.