Engine Rev in Park

When I start the 3.2v6 rodeo it idles really low and tries to bump itself up to stay on so it is constantly just reving up and down by it self. it will eventually cut off. Now if you put the car in gear, the idle jumps up and it stays on. only in park it does this. any ideas what needs to be checked

Does it do this all the time, or just after driving it for a while then shutting it off and restarting it??

Sounds like the idle air sensor needs cleaned.

all the time. I actually have installed a new idle air sensor. the cel was on with that code. looking back, it didnt act up until after the replacement. i assumed it was ok bc the light went off and hasnt been back. also i didnt notice the problem right away

I do have a nagging squeakiy belt. I tightened it a while back and the sqeak left. Now it squeaks again. Are there any components that would make if behave like this if a belt was loose? I vaguely remember hearing something about an "idle Something" that is driven by some belt?

You know what I'm thinking is perhaps your alternator is losing charge with a worn out belt, thus the truck is raising the idle to keep volts up to keep the truck running.

If your belt is not new and just started squeaking, it's worn out and needs replaced....start there.

Try cleaning your throttle body, etc. I have had this happen before with a sticky throttle body.

The Throttle body is spotless. Had to deal with all that recently with the EGR and CEL. I'll try replacing the belt. Also noticed that it DOESNT do it all the time. Sorry for the misinformation.

I've had an intermittent high idle in park after driving. It happened a couple of times in the last 5 years, then it happened almost with every trip out last week. I put the code reader on it despite not having a cel on. A code for the TPS came on. Swapped the TPS and the issue is resolved. I'll also add that I had low tranny fluid due to a small leak that I fixed at the same time. Don't know how they are related, but... I might try looking at what the TPS is telling you when you get the high revving.

EDIT: It seems you are saying that the idle is low, then jumps to where it ought to be in D? That would be different from what I described above...

your EGR valve pintle is more than likely hung open. clean it

Speak of the pro.....where you been 2eyefish??

the egr valve is new

If you replaced the idle air control did you install it correctly (not pinching the orange 0-ring)? And did you clean out the orifice completely? What was the condition of the one you pulled out?

Here's a thread detailing what I did today regarding some similar symptoms.

http://forum.planetisuzoo.com/viewtopic.php?t=28341

sweet I bought a new one ($40) our salvage yards are crap here (pay less for a new part) I did notice the difference in our procedure....you cleaned the housing for the IAC while I just blindly installed a new one. the CEL went off so I didnt think much of it (P0401)

If you replaced the idle air control did you install it correctly (not pinching the orange 0-ring)? And did you clean out the orifice completely? What was the condition of the one you pulled out?

Here's a thread detailing what I did today regarding some similar symptoms.

http://forum.planetisuzoo.com/viewtopic.php?t=28341

Had time todya to take off IAC and it was very clean and so was the hole it site in. I must have cleaned it too when I took off the throttle body. I'bought new belts today. will update