I have a '04 envoy XL with a really bizarre idling problem. My mechanic can't seem to figure this one out so I'm hoping the experts here at envoyforums.com can provide some much needed clarity. Here's the issue:
While idling I am getting some itermittent (it only happens every once and a while) fluctuations in RPMs. It drops down to about 200RMPs and then revs back up and then drops down again, over and over while in idle. Sometimes after a few times of doing this it will actually stall out. No problem starting right back up though.
Now here is the really weird thing...It only happens when the blower fan (for the A/C / heat air control) is on. If it starts up, I can always make it stop by turning off the air.
The really, really weird thing...I can always trigger the problem by turning on the air recirculation blower fan setting. As soon as I push the button to recirculate air, it will trigger the problem every time.
This problem seemed to start right after I got a dead battery and replaced both my battery and the main (125 amp i believe) fuse on the outside of the fuse box. For this reason, I think it must be something electrical related.
Ideas? Any help is greatly appreciated.
Tags: 2004, envoy, Fluctuating, GMC, idling, rpms, XL