Hey Guys! This is my first post here and I hope someone out there will be able to help me! I have an '87 iroc-z with a 5.7 TPI in it. Recently the RPMs have been surging wildly in any gear, whether it be drive, park or neutral, and the car has been stalling out. Took it to the shop and the mechanic said it was a faulty IAC valve, so they put in a new one. Just got the car back today and the RPMs are still violently surging, although not so much in drive anymore. Havent had it stall on me anymore, but this issue is still frustrating. Anyone have any advice? Checked all the other post but no one has quite the same symptoms as me Please help!

 

Check your vacuum lines. I've got the same ca/engine that had the same problem. Vacuum lines were old cracked and leaking. If they are the originals, replace them. It's not a hard job, just time consuming. Any auto parts store carries them.

 

im gonna check those out tonight, but I have a feeling that it might be electrical too, my voltmeter is also surging.