tcanthonyii

Ok so I snagged this thing today for a nominal fee. Ok Free!

Anyhow it's got 135k, new fuel pump, tires, battery, alternator, belt, brakes blah blah blah. Engine seems strong (good oil pressure and seems to run ok...for a bit). Little rust. Just some surface here and there in the usual places and a big hole in the front rocker. Leather interior with all the upgraded goodies. 8 years of maintenance history with receipts.

Anyway they gave it away because when it warms up (the truck that is) it doesn't like to start. So I drove it .5 miles to my buddies building. Man no power. Sounds like a hissing exhaust leak. When it completely warms up you can give it juice and it does nothing. Pretty much dies. Plus the intake sounds like a vaccuum cleaner.

I'm really thinking it's a plugged catalytic. Anyone else have any ideas? I'm thinking of turning this into my daily driver to keep miles off my '00 silverado when i'm not riding my MC. Oh it came with a full tank of gas too!

Any tips or tricks I should know about these? I've never driven one let alone been inside one. I know nothing about jeeps in general.

Thanks for the help gents!

T.C.

Bustedback

I'm betting on a plugged cat. Put a vacuum gauge on the intake, if it starts to read pressure instead of vacuum, then you have a plugged cat or exhaust.

Zj heep

X2 replace the fuel filter to.

tcanthonyii

Well it's not the catalytic, or plugs, or cap, or rotor or wires! Still totally stumped here. New fuel pump last fall as well as filter. Less than 1000 miles put on it since then.

Another symptom I realized today. It sputters horribly between 1k and 2k then will rev decently all the way through. If I push the foot feed all the way down it's falls all over it self and WILL NOT rev at all.

Total loss here guys. Any help is much much appreciated.

Bustedback

Might have a dead spot in the TPS. Whats the tach needle doing when the engine is falling on its face? And now that I'm thinking about it, how old is the gas in the tank?

tcanthonyii

God only knows how the gas is in the tank. 6 months maybe. I'll have to look at the tac tomorrow. 6 months on the gas shouldn't make it too terrible. I 've had cars with 8 year old gas not have these symptoms. Although the thought has crossed my mind that that could be the problem. Except they said it was doing this when they quit driving it.

tcanthonyii

OK so the tach needle just stays in the same spot or drops a little bit when it falling on it's face. I went to pull the tps off and it seems impossible. Do I need to take the whole intake off off? I was thinking may be the IAC (that's the other sensor on the intake right?) is dirty as well.

I read online somewhere that unplugging the o2 sensor might fix it but that made it worse. I hooked a fuel pressure gauge up to it and it said 0. There no way it would even run or accellerate correctly if it had 0 right? I need to check my gauge again as it may have not had it hooked up right or something. The fuel pump is 6 months old as is the fuel filter.

I'm totally lost here guys. Any help is greatly appreciated.

Bustedback

A new fuel pump does not always mean a good fuel pump, new puppies die too. They could have installed a cheap POS pump, or just replaced the pump part, not the whole module. I always cringe when somebody says they just replaced the fuel pump and it still does not run, makes me think they screwed something up during the install or they misdiagnosed the problem. You have to go back to square one and check everything all over again and take what the seller told you with a grain of salt.

tcanthonyii

Yup I agree. Just stating the fact. I do have the reciept from the work done. It was done at a shop just a few blocks away from me. LItterally like 2 blocks. I may pay them a visit tomorrow just to ask a couple of questions.

Any other ideas?

cdawall

get a fuel pressure gauge and make sure its over 50PSI. change the fuel filter again just to make sure thats not it.

1996jeepgrandcherokee

make sure the plug wires are on the right way. also when the jeep is cold, unplug the crank position sensor for a while and then plug it back in and try it

dave1123

This one for the vets. Could it be a loose intake manifold?

vadergator

aside from the IAC or TPS or MAP / MAF sensors; have you checked your ignition system? your ignition control module has temperature related stalling problems. this causes sputtering, poor fuel mileage, power loss, or engine shut-off after motor warms up. a rich fuel mixture is a classic sign. usually you have a strong fuel smell in the exhaust when the motor sputters. motor will die suddenly and without warning. with an internal short or one of it's relay sticks closed, the module will crank up and run fine. it will stop running anywhere from a few seconds to a few minutes later. the motor may not restart immediately. but, will crank again if left to cool down for about 10 minutes. might want to check your external ignition switch box as well. with everything computer driven on the idle / air to fuel mixture ratio's / and timing on these jeeps; i'll betcha anything the after warm-up no crank problems are ignition related. they give off some of the same sneaky, puzzling symptoms as the other sensors. don't want to step on no one's toes but, i thought i would throw that at you. just went through 6 months of hell with my 97 jeep GC and it turned out to be the external ignition switch box. alot of wasted time and money on parts that never fixed the problem. good luck p.s. on a couple occasions, i experienced total loss of fuel pressure and had no spark conditions at the same time out of nowhere. that's 2 towing experiences during the trials and tribulations of my Jeep-induced road rage epic journey.

vadergator

just thought i would add in that the loss of power accelerating and the no / low rpms are definitely the Idle Air Control and Throttle Position sensors. probably need to thoroughly clean your throttle body as well. the rest is ignition related, guaranteed.