Idle Fluctuation
#1
Idle Fluctuation
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.
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.
#3
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.
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.
Last edited by Tony71502; 11-04-2009 at 02:33 PM.
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50, car, cold, fluctuates, fluctuating, fluctuation, fluctuations, ford, idle, jumping, mustang, start, startup, supercharger, throttle