Okay, here's the facts: bought this VERY NEGLECTED 05 Envoy 4.2., 149K miles.
Running on 4 out of six, replaced 2 bad coils, Replaced unbelievably dirty air filter, sprayed MAF sensor really well, removed throttle body and cleaned years of hardened carbon off. Runs pretty smooth now...slight vibration which I think is motor mounts. But.... IDLES faster than it should.
My other two 4.2s (Trailblazer and Rainier) Start from COLD around 1200rpms and very quickly calm down to 650.
Not this Envoy. Starts up to 2000rpm and slowly gets down to 800.or 900. Lowest idle I've seen is 800.
When warmed up and stopping for a red light the rpms SPEED UP as the transmission downshifts.
It's now idling around 1000 while I'm stopped at the light and holding it back with the brake.
In other words;; IT BEHAVES LIKE A CARBURATOR ENGINE WITH THE CHOKE STUCK ON.
It's tempting to try to Blip the gas pedal to make the choke come off and the speed come down, but, of course, there is no choke.
Transmission fluid and filter change tomorrow.
ANY IDEAS?
Thanks!
Running on 4 out of six, replaced 2 bad coils, Replaced unbelievably dirty air filter, sprayed MAF sensor really well, removed throttle body and cleaned years of hardened carbon off. Runs pretty smooth now...slight vibration which I think is motor mounts. But.... IDLES faster than it should.
My other two 4.2s (Trailblazer and Rainier) Start from COLD around 1200rpms and very quickly calm down to 650.
Not this Envoy. Starts up to 2000rpm and slowly gets down to 800.or 900. Lowest idle I've seen is 800.
When warmed up and stopping for a red light the rpms SPEED UP as the transmission downshifts.
It's now idling around 1000 while I'm stopped at the light and holding it back with the brake.
In other words;; IT BEHAVES LIKE A CARBURATOR ENGINE WITH THE CHOKE STUCK ON.
It's tempting to try to Blip the gas pedal to make the choke come off and the speed come down, but, of course, there is no choke.
Transmission fluid and filter change tomorrow.
ANY IDEAS?
Thanks!