I have a 98 jeep cherokee 4.0 4X4.

A few months ago my jeep ran out of fuel. Ever since then it has had a sputtering, lose of power. It starts up fine, then after a couple of minutes it starts to lose power. It'll last about 5 minutes or so then it's fine. It seems to happen around 190 degrees while it's warming up. It does it almost every time I start it. I have had 4 different shops look at it and spent over $600 and nothing has helped. They have changed the fuel pump, filter and pressure regulator, coil, and air control valve. They say the lines and injectors are clear. I'm to the point where I just want to sell it and be done.

Does anyone have any suggestions? I'm desperate and about to get rid of it if I can't fix it.

 

go to autozone and pick up a map sensor for 20 bucks or so.
its the sensor on the firewall above the intake manifold
oh and while u have it off check the vaccum line thats connected to it

 

1. Assuming that you have fresh plugs, plug wires, distributor cap and rotor in there?

2. Any check engine light? Even if the answer is no, I would put a code reader on the computer to see if there are any stored codes that might provide a clue. There are even some "soft" codes that don't set a check engine light.

 

It's had a recent tuneup-changed nothing with performance. It had a code. Mechanic said it was either for a bad coil or crankshaft sensor and thought it was coil causing problem not sensor.
I read some threads on here that sound like it might be o2 sensor but he told me today that there would've been a code for that.
I forgot to ask about map sensor. I'll ask him tomorrow about that. I want to do more research before I buy anymore parts. I have spent way too much money already.

 

With a code, the devil is in the details.

Post up the EXACT code number(s) here for the most accurate responses.

The codes are absolutely critical in troubleshooting a problem.

 

I didn't know what the code was so I had my mechanic check again and o2 sensor code popped up. He said it didn't come up last time. So he tryed checking it out and upstream sensor has been replaced before and it is crossthreaded and can't be removed. He says it needs to be cut out and rewelded. But I guess it is bad since the code came up but he doesn't seem to think that would cause my problem. (BTW I work at a tire store and he's the mechanic that works there)
Does anyone know of a way of testing the sensor before I spend the time trying to find someone to cut and weld my exhaust? I want to make sure that is my problem before going through all this trouble and being disappointed again.

 

The code that came up was P0420. Also no vacuum leaks.

 

The P0420 is for catalytic converter efficiency, so this should not be related to the pre-cat oxygen sensor.

Could be the catalytic converter itself here............

 

Do you think that would cause the problem I'm having?

 

yes it could. Excessive back pressure in the exhaust will make it run horrible. You could either go under there and drill some holes before the cat and see if it runs better or take a temp gun under there after it has been running for a few minutes and take a readingg before and after the cat. If there is a big differential temperature difference that cat is more the likely plugged off.

 

I will check that tomorrow. Thanks everyone for the info!

 

my jeep is doing that same thing i think, its a 98 too, starts up fine then a little bit later starts losing power , trying to go dead if in neutral or park, if in drive it wont go any where no matter how hard you mash the gas, but after 2 mins or so of this it is fine till you cut it off and start it again.... ive replaced the nss, mine was bad had a code for it, and the tcu none of that has helped yet. i have about 2 threads on here for it lol. let mme know if you figure out what is causing this.

 

Try looking at ur fuse under the hood. I had the same problem with my 98. It's the little fuse box, mine was a blue 15 am on the left side if ur facing the windshield. Mine was blow and I replaced it and it stoped