Tony71502

When I start up the car at idle the rpm fluctuates almost to the point of stalling. This tends to go away after about 20-30 seconds. After that the idle fluctuation is about 50 rpm. There's no problem when the throttle is open even the smallest bit, not that I can tell.

Would this be as simple as a bad IAC? The IAC on there is only 2 years old and still clean.

Or could this be some tiny vacuum leak that almost fully closes as the engine warms up? 20-30 seconds doesnt seem like enough time to fully warm up from a cold start, though.

mjr46

make sure the throttle body is clean and the mass air meter is clean and no vaccum leaks

Tony71502

Thanks Mike.

We cleaned out the MAF and IAC two days ago and that didn't help. I'll try cleaning the throttle body out. The TPS is fine. I sprayed a healthy dose of starting fluid around and there was no leaks. The only leak that I had was between the EGR spacer and the upper intake plenum. That's fixed.

The only codes in the computer are EGR and thermactor/thermastor related. No CEL is present. The codes are benign.

The car has power. Just the B cam in a stock block spins the 275's through second gear. Granted it was about 50 degrees out...

I'm going to grab a new IAC soon and see if that helps at all.

My intake system is 19 years old... I may just start upgrading.