TheDog
Registered User
This problem started months ago and I'm finally getting around to posting about it. I've got a 1990 SC auto. I'm thinking this problem started shortly after I installed my magnaflow resonator and Flomaster resbacks. Of course the problem is intermittent too. Car starts up just fine. Usually within 15 seconds, the car will groan loudly (sounds like air resonating through something under the hood but I could be wrong) and surge up to a 1250rpm idle. It'll stay like that for a while then the groan will go away and the idle will drop back to 700 or so where it's supposed to be. If I drop it in gear, hold it for a second then put it back in park, it'll USUALLY force the groan and rpm surge to stop. But sometimes it won't stop it. You can imagine how hard I have to apply the brakes to hold the car still. It'll do it periodically while I'm driving too. So while I'm cruising, the groan may come on and force my tach up to 1250. I'll shift into neutral, the engine will soar to 1700 for a moment (probably because there's no load all of a sudden) then drop to it's correct idle. I'll put it back in gear and it'll behave for a short while then repeat.
The engine is all stock. What gives? Any ideas? Thanks!
The engine is all stock. What gives? Any ideas? Thanks!