Stall / Surging idle, no CEL on though

[phil_01_s]

Okay, so I've had my 01 Trooper stall on me at low RPM about 4 times now, no CEL. Once after it stalled I gave it a little gas after starting it up, it reached about 2000rpm, then I let off the gas and it dropped to 1500, then back up to 2000, back to 1500, then up to 2000, over and over until I turned it off and restarted it. Same problem upon restarting it, no CEL though, drove around the block, returned to the driveway and no idle surge in park even after restarting. Stalls have all been soft stalls, no surging of the vehicle, 2x it happen while moving and I didn't notice the engine had died until I had no power steering, 2x times have been while parked and idling. The throttle surge has only happened once.

I've read the FAQ but it seems the EGR problem is always accompanied with a CEL.

I've got 2500mi until the 2nd owner warranty expires (i've got about 57.5k on it). I know the EGR won't be covered under warranty. PCV was replaced and throttle bottle cleaned 1yr/10k miles ago. Someone on ITOG mentioned a possible cracked intake manifold gasket, which could cause same symptoms, and this would be covered under warranty.

So what's everyone's best guess diagnosis? I guess I'm concerned about it being a cracked intake manifold gasket, and would like that to be fixed if that's the problem, but I do not know really what would be involved to check this myself (no repair manual). I looked at the EGR FAQ and that seems like I'm capable of DIY for me, but I don't know about checking the IMG myself.

Could there be possible fault codes stored w/out tripping the CEL?

Thanks,
phil

[amigo-2k]

Cleann the EGR yourself. See what happens.

If that is no help then take it to the dealer since it is still under warranty. If the EGR cleaning is no help then it is most likely a bad IMG.

[phil_01_s]

Cleaned the EGR following the FAQ. Wasn't sure how much of the o2 sensor safe carb cleaner through, I'm guessing I did about a 1/3 or so of the can. Installed a new PCV and a new air filter.

My EGR gasket is a little rough and has stuck to the EGR around the vacuum and exhaust holes, I didn't replace it, but just thought I'd mention.

I didn't take off the throttle body b/c I wasn't sure what all was involved in that (no manual). So I'm not certain how clean the tube into the intake is.

Reinstalled everything and started up after leaving the battery unhooked for 15min. CEL. Looked under the hood and I never hooked power back up to the EGR. Unhooked battery for 15min, hook up EGR electrical connection. Restarted and no CEL!

Maybe I'll know by next week if what I did helped or not b/c it was pretty randem last week. Thanks for putting together the FAQ, that helped tremendously. If anyone can show pics of removing the TB I'd appreciate it, I picked up the 3/8"ID tubing to flush it out already.

Thanks,
phil

[rodeo02]

EGR issues usually result in a CEL. A bad intake manifold gasket may not. I'd look into the IMG, a freebe fix under warranty!

G/luck
Joel

[phil_01_s]

Are there any other symptoms for a bad IMG? There is an accumlation of dirt and stuff at the joint of the IMG. Well I think it's the IMG, directly behind the throttle body sits the intake manifold, correct? the first joint under it is what I'm assuming has the IMG.

I just want to be prepared if I do take it do a dealer so I feel fairly confident it what could be wrong and also not let them take me for any work that doesn't need to be done. The Isuzu place as well as a few other places owned by the same person don't have a great rep around here.