Ok, I have tried pretty much everything, and im getting pretty stumped by this too.

I put a 60mm MP TB on it, and it idled at 1500 four months ago. Made a new gasket, no help. Checked for vac leaks, no help. In a final attempt took the IAC out, screwed it out a few turns, and I got it to 1k +/- 75 with a 150-200rpm idle hunting. Not perfect, but alot better.

I blocked off the EGR valve Saturday, and for two dies my idle was back to normal. 900 +/- 50. Third day and since them im idling at 1100 with a constant + 300rpm idle hunt. If I turn the AC on, im at a constant 950ish.

I replaced all the engine bay vac lines, and im about to go plug the EVAP port to see if it helps.

Any ideas?

I may try to screw out the IAC again, or make a manual adjust like Neons. I do have a can of Seafoam, maybe ill put that in it and watch for white smoke to puff out.

BTW - tested the four IAC's and TPS's I have, all are well within spec, ive also swapped them into to no avail.

Thanks!

hmmm.... stumps me too. Mine idle hunts too. Bounces from around 800-1000rpm. But its more of a lope. Pretty sure its my timing, cam gears are off by a few teeth. But this didn't happen until after you put the 60MM TB on? Did nothing else?

if you are searching for a vac leak, shouldn't you be using smoke instead? you are looking for smoke being pulled in. BTW I'm not advocating smoking he he

Yeah, MP started it. Stock would idle normal.

I think next up is RTV as a TB gasket. Then if that doesnt help, ill do the intake mani gaskets. Yay!

whats your vac at idle? finding that out will help you determine a pre or post throttle plate. aka iac problem or gasket problem.

also, i would try loosening the 2 10mm bolts that set throttle cable tension and let the cable "flop", your problem could be a partially open butterfly and the iac is hunting.

also if you think its a post butterfly leak, if you have a can of propane, run it along any gasket surfaces and hear for an idle change, even better if you have a wideband gauge or some sort of scan tool, just watch for o2 reading to richen up. If they do when you are at a certain area, then you know you have a bad gasket.

Yeah, I did the cable adjustment...

Ill try the propane, but we did that last weekend, no results.

Maybe ill get a vac gauge and try it.

Originally posted by teklein
Yeah, MP started it. Stock would idle normal. I think next up is RTV as a TB gasket. Then if that doesnt help, ill do the intake mani gaskets. Yay!

Did the 60mm TB come with its own new gasket or what? RTV would be a good idea. Just seal it up and hope for the best. Would be great if its just the TB gasket. I would try the RTV like you said. Good luck.

Didnt come with a gasket, I made my own out of gasket material.

I dont think it would be the material, as it worked fine at a stock TB gasket for miles and miles :shrug

Hmmm ya, that should have worked. I have that as a TB gasket right now since i had some laying around instead of paying for a new gasket. I don't know why yours would be leaking though. Just RTV it and hope it works. If not, its got me stumped also. :shrug

Any luck Tim?

Tonight should be the night.

New gasket on the way from Modern for the TB.

Im also gonna monitor the voltage on the TPS, Terry and others were telling me TPS's can go bad and freak out, so the ECU sees open/close/open/close.

Hopefully she will be idling normal tomorrow.

I also think I have a slight miss too, so ill put new wires and plugs in :P

cool. Let us know!

Originally posted by teklein
Terry and others were telling me TPS's can go bad and freak out, so the ECU sees open/close/open/close.

Seeing as it's a chrysler TPS and they're known for going bad...

be thankful you don't have an automatic jeep cherokee, mine went bad and it grenaded the transmission by kicking it in and out of overdrive at cruising speeds.

Tested the TPS today, it was fine.

It started whistling so loud when the accelerator was untouched, you could hear it in buildings.

I took the TB off, and put my new gasket on that I ordered from Modern. Everything is fine now! The gasket that was on there was CLEARLY leaking right out the side. I dont know how I missed that :P

No whistle, awesome 850rpm with no hunting!

when a problem is solved on a 2gnt, unlike any other feeling. I knew you'd figure it out.