I searched the Internet for this problem I have with my 88 3vze 5 speed with no luck. The engine starts right up now that I worked some things out, it use to take a lot of cranking on a cold morning. Now it will idle about 1200 RPMs until it starts getting halfway to operating temperature. Then it will start loping for few minutes 6-1500 RPM a second only without applying throttle. As soon as I put pressure on the throttle it will behave normal. When it gets to 180F it idles normal. No issues on a warm morning, No power loss, engine does not die, and I don't notice it decelerating in gear.

Hoping someone will have an idea.

 

No one has an idea. I was talking to a few guys at work one guy says it could be the knock sensor. I don't think he is right, plus it doesn't give any codes.

 

What have you looked at already? Cleaned the MAF? Checked spark plugs? Vacuum leak?

Have you looked at the FSM poor idle diagnostic section?

 

I looked thru the FMS nothing describes the symptoms. A few other things I noticed, the smallest load to the engine like dragging the clutch it will behave normal. even slightly turning the steering will stop the loping. Very strange. I also took the intake off cleaned it all out, no difference.