2K idle HELP - Third Generation F-Body Message Boards

70gmc · 07-30-2009, 12:05 PM

I have a 92 RS camaro 305 TBI. It idles anywhere from 2k to 2500, regardless of hot or cold. It is not throwing a engine code light. What could be the cause of this? any sensors i need to look at? ways to test them?

I have tryed the search engine and cant really find anything.

This is my dailydriver so ineed it fixed asap. Help is GREATLY appreciated.

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Ronny · 07-30-2009, 03:36 PM

Idles at >2000? Check linkage to see it is not hanging. Cycle the IAC from the ALDL and determine it is functional. And check for VAC leak. I had a nipple plug on one of my vac sources on TB unit crack and it was leaking. Simple 25 cent fix. Dropped idle 200 rpms. Is .bin A-OK? Make sure on ekey on engine off you get the blink. A corrupt bin will idle 2000 rpms(that was 2 weeks ago).

70gmc · 07-30-2009, 06:09 PM

can i get better explaination of all that. I am not familiar with these cars.

kkingsrulee · 07-30-2009, 06:25 PM

Check for a vacuum leak. Did you perform any repairs on the car lately? I changed the thermostat on my car once and didn't reconnect a small vacuum hose that goes from a small vacuum plug on a clip attached to the upper radiator hose and it idled at least a good 500 rpm higher than normal before I noticed it.

70gmc · 07-31-2009, 12:00 AM

alright guys messed with it alot tonight. I tested the IAC MAP IAT and they all tested good. It seemed to be squirtting to much fuel so i unplugged one injector and it idled down to about 750 and a little rough which was to be expected. but my point is one injector plugged in kept it running and slowed the rpms.

To me if it was a sensor wether it be 02 or what not then it should have a SES light which it doesnt.

So is it posible its a bad regulator. how can you test it?

Ronny · 07-31-2009, 10:23 AM

Reg failure not likely. for it to idle that high it needs air. Probable VAC leak.
Locate linkage on TB. Locate TB shaft. try to move it L-R up down. wiggle it . is there slop? I believe any carb shop can rebush it. you can remove it easily to drop it at shop.

If you jump A-B on ALDL(search for location) I will guess it is top row 2 slots far to right IAC should cycle. Look down from top of TB and confirm it is closed. I had two IACs on Vette. One stuck open(failure) and I had high idle.

Check all vac lines running to TB. One may be split aways from TB on line.

spray carb cleaner around base of TB as base gasket could be wrong style OR defective