Hi everyone. I have a 92 Jetta (1.8 gas w/AC) that has recently started to hunt idle once it's warmed up. It's intermittent, but it's happening with greater regularity. Started a couple of days ago, during some really nasty cold weather up here in Canada, but is still happening.
When the engine is cold, it runs perfectly. As it approaches normal operating temperature, the hunting begins, gradually at first, worse as time goes on. I can keep my foot on the gas, and the RPM will stay steady. Acceleration is smooth. Only idle is affected as far as I can tell. Sometimes, even though it doesn't really "hunt", if I take my foot off the gas the RPM will drop to 100-200, then bounce back up to around 850.
I've done some research, and I think it's pointing to the Idle Stabilizer Valve. Maybe the cold weather made it "sticky" or something? I don't think it's an ECM problem (god I hope not, I can't afford that right now). I just want some second opinions, as I'm really not sure where to start looking for the problem.
Thanks! Chris.