pbocco

We've wracked our brains out trying to get my 01 cherokee sport to run. It runs really rough and stalls...then starts up and runs smooth for a few minutes...then rough and stalls. So far we've put new cam and crank shaft sensors, tried a new coil pak, put on a new gas pressure unit, checked the wiring harness for shorts, among other things that I can't even remember. This has been going on for over a month and I'm into it for well over $600.00 so far. Seems like the last option ( the dreaded dealership) is fast approaching. Oh yes...I just remembered the new computer we put in at the beginning of this ordeal...
Any help would be GREATLY appreciated.
Thanks

aintlifegrand

Could it be the cat is clogged up?

Kalali

Any engine codes? If it acts up as the engine warms up, it could be one of the temp sensors; air temp sensor which is on the intake manifold or coolant temp sensor screwed into the thermostat housing. Both are relatively cheap to replace.

sgjii

I am a recent owner of an 01 Cherokee Sport and I had severe running issues.

When I first got the truck, I started down the road of tune up and fluids to start bringing things up to spec.

For spark plugs, I brought my "Euro" school thought from VW/Audi/Porsche/Benz, that Platinum plugs are better than copper. The truck ran like crap on the platinum plugs and even worse when warm. That is when I found this forum and some quick research informed me that this 1950's design "tractor motor" just wasn't meant for these new fangled spark plugs. I went with the forum recommended NGK Coppers for an 01, Purrs like a kitten! I would not have believed it had I not experienced it.

I guess I would start from the keep it simple school of thought. Any parts changed/replaced or improved (kinda like my idea for good spark plugs)? Any parts I replace on the Jeep at this point are going to be OE, including a Mopar oil filter.

Is the gasoline fresh and checked for contaminants?

tjwalker

Yup, I have the same question. Any codes?

RTorrez1

Checking for code should be your fist move when ever you start having any problems. It can save you a lot of money and headaches.

KicknUpMud

Could be your upstream o2 sensor? My xj would start and run good for like 30 seconds then start stalling and bucking forward even when i had my foot on the break. Put in a new upstream o2 sensor (sensor on exhaust by motor,manifold,ect..) and its stopped. Hope this helps some.

CoffeeCommando

It could be anything from a fault electronic component (which codes will indicate) to a rusty ground. You need codes.

Also, don't forget that a failing check-valve on a fuel pump could cause stalling. Is it unusually hard to start in the morning with doing the RUN-OFF-RUN-OFF-RUN-START cycle? The Run-Off cycling helps build up pressure in the fuel lines that the check valve lets bleed off every night (as it begins to fail).

But if that was your problem it would only be once in the morning and be gone once it's warmed up and ran for a while. It's when the vehicle sits for a while and has time for the fuel lines to cool off that it comes back into play (hence mornings).