Idle problems

[tderrick]

Just got the GT back after getting the AC redone. The tech asked me if the car always had a lope at idle. I thought he was just talking about the typical 5.0 bumpy idle.

The idle has a weird up and down sweep to it over a couple hundred revs. Not the normal
computer reset hunting. I did reset the computer again.

I just want to make sure it's not something simple before I have to take it back to him.
It's just a pain to drop it off.

The cold idle is fine (closed loop?) it starts heavy loping after warm up (open Loop?)

What is the main component to check for warm engine idle?

EGR maybe...

tia

 

[HISSIN50]

Your loops are backwards.

Vac leaks are the place I start checking when there's a slight up-and-down idle hunt.

Always a good idea to check codes to see if a clue is stored.

Good luck.