1989 IROC-Z 305 TPI 5-Speed, just replaced EGR then had major vac leak, but found it after 5 days, well thats another story. Anyway now I have a very high idle, the curb idle screw is backed out all the way and it is not even touching the throttle, its acting like i have my foot on the gas, the throttle does not feel like it is stuck I can move it back as far as possible and it still is very high.

I replaced all the gaskes to the TB when i did the EGR, I replaced the TPS & IAC about 6 months ago because I had the same problem, it brought the idle down , but it still did not bring it down to normal, could they be bad again?. I also do not have the OHm or Volt meters to tune them properly. And I really dont want to spend an arm and leg at the dealer to have the "diagnose" the problem for me. you know what i mean, i dont want to put their kids thru college by fixing my camaro.

any help please.

Bombero

 

BB,

How is the PCV valve? A sticking or mis-applied PCV can cause a high idle due to excessive air (leakage).

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Vader
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"Let the bodies hit the floor!"
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I did not even check the PCV valve to see if it was bad or not, I just replaced the hose itself im sure its time to change it. I had no idea that would cause an idle problem. I will go and replace it this morning and let you know what happens.

 

Sounds like you have a vacuum leak still, might be one of the gaskets you just replaced. Tough to say without being with the car.

 

When you replaced your IAC did you clean the passages?

When you had your plenum off did you clean the EGR passages with a pipe cleaner and carb spray? This passage was totally blocked on my plenum.

 

What do you mean by "very high." I've been as dumb as anyone in this area, in fact I drove to a mechanics after being baffled by a leak where I had forgotten to reconnect the pcv hose! It had a rough idle but still ran relatively well. Since the car runs, you probably have the plenum/runners assembled right - in my experience that's the only sort of massive leak that will keep a tpi from running. I had the same problem for awhile but I would definitely do the iac/tps adjustment as described in the tech section. You may have to repeat a few times to get your idle where it needs to be.

Edit: Ooops just saw how you don't have the tools to tune the iac or tps. Well my advice is to get them if you plan to own a tpi car. All you need is a cheap ($10-$20) voltmeter to check the tps. I use an adapter from lingenfelter that was about $10, although you can get away with good jumper wires. You can at least do the iac part of the procedure, then if that doesn't help check the tps. The first time I checked my tps the previous owner had it set to .33V at idle!

[This message has been edited by I ROCK (edited August 13, 2001).]