Irratic Idle on Cold Start

[Guest sonnyny]

I'm experiencing an idling problem with my 96' 2.5 GT 85k miles at start ups only and only when the car has been sitting and completely cool. Usually happens in the morning and not all the time. It idles correctly at 1st for about 5 seconds, then sputters for 5 to 10 seconds, then revs up to about 3,000 rpm, and then levels off to a correct idle speed. I just purchased the car last month and the problem has come and gone. I recently replaced the spark plugs, air filter, and fuel filter which seemed to cure the problem but it just happened again. The car runs fantastic otherwise. Anybody have an idea ?

[Guest Legacy777]

I'd try running some potent fuel injector cleaner through, may even want to run it on a half tank of gas.

 

Other thought is idle air control valve sticking.

[Guest remarcable]

All the hoses that connect to the airbox (where the air filter is) tight and secure? Airbox back together all the way?

 

PCV valve generates suction when you put your finger on it and CLICKS when you remove the finger?