piezzi

110,000 miles on my '03 and it's always ran like a champ. This week it died on me a couple times while driving slow or idling. Only does this intermittently, like a couple times a day. Also will stumble when excellerating past 68 mph, but then keeps on running. And it intermittently sumbles at idle or take off. When it stumbles and/or dies, it seems like an electrical cut off rather than a mechanical/engine issue. I usually average 20 mpg and this week I'm only getting 16.

Any thoughts on why?

xtreme velocity

Fuel pump? Fuel filter? Something in the lines? Spark plugs(unlikely to cause that though).

nick_n_ii

Also check the throttle position Sensor on the throttle body they go bad..

RRAM

Money is on the tps. I just had to do mine with the same problem. Cost me 95bucks and it was in stock. I wonder why. that was on my 04 with a 4.7

piezzi

I swapped out the TPS this morning.....but it didn't fix it. Still sporatically cutting out on me and getting low mpg. It drives fine on the freeway, but at lower speeds (usually while idling or close to it) it will die. I've noticed when it's acting up sometimes the gas guage will go lower and then the "almost empty" light goes on....even though it's got plenty of petrol. Usually it will start right back up after it dies, but starting yesterday it's having worse episodes where it doesn't want to start or if it does, it idles fine but dies when put into gear. Then a few minutes later it will be okay.

Any more ideas?

nick_n_ii

throttle position Sensor is what I'd be betting on... My brother had same prob on a '99 XJ the TPS fixed it...

RRAM

when is the last time you changed your plugs? they do go bad and it may even be one of the electronic spark coils on the plug. You would probably need a code reader to see which one. I had one go bad on my durango. Chrysler told me they seen a spark problem with number 5. It didn't actually stall but I could tell something was not quite right at times. Plugs are pretty cheap and easy to erase from the equation.

jamaicanmecrazy

Autozone and Parts America parts stores scan for free.
MAP sensor perhaps? Besides the other thing folks have listed.
I also change o2 sensor(s) all the time to regain MPG.
A bad spark plug wire will do the same things you are talking about. Spray them with water in a spray bottle and look for arcs in the dark.

Mukyluk

tps, plugs, injectors, fuel pump, fuel filter.
its sad my jeep gets less mpg then my sports car.

piezzi

Turned out the battery ground going to my engine block was corroded inside and wasn't allowing a good connection.

There are a lot of threads online about GC's of all years having this cutting out problem, and from what I can gather, folks will throw a lot of $ at the problem changing out sensors when most often it's a ground problem of some sort. So if you have this issue with your GC, my suggestion would be to make sure your battery ground to the engine block is solid AND also check your onboard computer gounds to the car body (inside the engine compartment on the passenger side). Older GC's apparently have a problem with the onboard computer cover's mounting screws being too long and shorting out the system.

Good luck!