ryan_lerv

..

VTJeep

CEL on? Sounds like a sensor issue, maybe o2, TPS, IAC, ignition coil.. Edit- what does it do at WOT while driving? Will it rev all the way out to redline area?

Edit 2- no, it's probably not the filter..

JeepStephie99

This. Any codes on? My 99 use to jump randomly. Felt like the trans was slipping but in reality it was the O2 sensor. Wires rubbed on the intake and grounded itself out. Codes came and went frequently.

ryan_lerv

C

JeepStephie99

Check your O2 sensor wiring. Around the intake. It's a common issues. Mine would run great. Until I hit a bump. And the wire touched.

Eisenschwein

I had an Olds Alero that started acting like that. I changed all sorts of sensors... ended up being the Catalytic Convertor being intermittently plugged because the stuff inside was breaking up. New Cat and she ran perfect. Not a cheap fix but worth at least investigating.

JeepStephie99

This too! Mine had a howl noise. Then one day home you could smash the gas. Rpms would go up and you'd go no where. Couldn't get it past 30. Cat ended up clogging.

Eisenschwein

Yep! Mine didn't howl at first but same thing, you could give it hell, would up the RPMs but no power. I thought it was the tranny too because it felt like a slipping trans. Ended up being a chunk of catalyst stuck in the tube.

ryan_lerv

My O2 sensors and wiring look to be fine. I'm pretty sure there is only 2, 1 before the cat and one after the cat

VTJeep

Well if it is fuel related, the bad news is the pump/filter assy is an in-tank, one piece unit. I suppose dropping the tank and inspecting won't hurt. Does it do it on hills? Used to get a lurch on this one particular hill, really long and steep.. Long story short, checked tank and there was sand and leaves and crap in there.. All because no CEL doesn't mean no stored codes that haven't tripped the light, might be an P0135 (or similar) stored in there.

ryan_lerv

So the fuel pressure is fine andi it's not a coil, sitting in the driveway with a new coil and the fuel pressure guage on it it will idle and then just die like someone shuts the key off. Fuel pressure is fine the whole time. Did that a few times and just kept dying, tried to drive it home and didn't make it 100ft, died and no start. Got it home and 2 hours later went to start it and it started right up.. Now I'm thinking it absolutely has to be a crank position sensor

Turbo X_J

CPS wiring fried up against the exhaust?
Have you checked the loom on the passenger side of the engine compartment?

toasterknight

Another thought. It could also be a vacuum leak. If it whistles a bit spray the vacuum lines with brakleen or something similar that is flammable and if you find the leak it will rev up slightly. Mine is doing these same symptoms and I have replaced both o2 sensors as well as the exhaust from the header back and it is narrowed down to a vacuum leak that I cannot seam to find.

VTJeep

Ha! I did this when replacing mine.. :/

ryan_lerv

Fixed the problem, turned out to be a bad crank position sensor