Car stalls/loses power (cold) then quickly accelerates
 

Hello,

It started occurring a few days ago. The car starts fine, but when I travel half a block or so, I feel the car loses power and slows down running rough. Even pressing further the accelerator does nothing. Then the engine rev's up and accelerates. After the engine warms up it drives fine. This happens when the car is cold.

I replaced the air filter which was clogged. This improved the performance. But after a day or two the problem returned but far less. I then cleared the ICM and that really returned power and I thought normal operation.

Now it's happening again though less. Though when it loses power the car doesn't run rough. The tach doesn't change rpm's. If I step off the petal a little and press it again the car gains a little power. I had no CEL's during all this.

Any suggestions.

Thanks

I'd scan for codes anyway.

Are the other regular maint items up to date - cap, rotor, plugs, ect?

Yes, all said items are up to date. I even checked the PVC valve. It's fine. Also checked for vacuum leaks with a can of throttle body cleaner. But on a old engine. No leaks found.

If I warm up the car for one a minute or so the car experiences stalling. After it warms up it drives fine. If the car is warmed up for 5 minutes, then it drives fine. When I first set the ICM it drove just fine the first couple of days even when cold. Still monitoring the situation.

Thanks

Hello,

The car continues with the same problem. I start the car cold and allow to warm up for a couple of minutes. While still in park I rev the engine a little and experience the same problems as when driving without allowing the engine to completely warm up; lost of power when accelerating, and even rough idle performance after I let off the pedal. Once it's hot it runs fine, for the most part.

Seeing that the problem occurs when the engine is cold but works fine when hot made me look at the catalytic converter. Doing some research, the cat operates at high temperature. At that point it's able to burn off the build up of gunk. In my case just enough so the car is able to operate. Any feedback?