My 85 IROC idles at 1450-1500 rpm about 99% of the time and the other 1% it tries to stall out unless I hold the throttle. Maybe a vacuum leak? Where would be the best place to start to fix it? This is my daily driver and my gas mileage really sucks right now. Any help would be appreciated.

 

Vacuum leak would be my first guess.

TPI or IAC issue would prolly be my second guess.

THOUROUGH VISUAL INSPECTION OFTEN RESULTS IN FINDING THE CULPRIT WITHOUT FURTHER DRAMA.

That being said, check out all your basics and work from easiest to test/inspect to hardest.

Busted vacuum lines, broken gasket edges etc can all be examined without tearing the car apart.

let us know what u find and give us info as you go.

later
Jeremy

 

I will certainly keep you posted. Hopefully it's not anything too serious or expensive.

 

I just bought a new IAC valve which I will install tomorrow. Hopefully that will fix it. I couldn't see anything like a blown gasket or anything like that so we'll have to see what happens.

 

hey mine did that for a wile to but did not stall. i bet it wont be the iac, and you can cleen those. anywho i checked all the lines, nothing. i gave up. i put a new iac valce in. tps sensor etc. i spent about 200 bucks on it. it was still running like **** and high idling. i took it to my shop and he reset my comp and cleened my intake manfild. runs so good now. give that a try.

 

I'll try that, although I'm still going to replace the IAC since I already bought it. I'm not sure what you ment by "cleaned the intake manifold". What exactly did your guy do? Do I need to pull it off the car? I know these are weak questions but I want to be sure that I don't do more harm than good.

 

yea i jsut cleened the whole air intake system. after 14 years, and 70 thousand miles later, it gets dierty. i jsut cleened out the plenum, runners and as best i could intake maifold. i jsut took the runners and plenum off. i probably got about 5-7 hp of lost hp back and better throttle responce. just get some TB cleener and use that. that way its burnable in your engine. thats what i did, worked better.

 

Fortunately the IAC was the problem so everything is running fine now. Thank you to everyone who offered advice.

 

try cleening your plenum and components out anyway. gives you abck some extra gas milage and power

 

That will be the next thing I do. Thank you for the advice.