Hello,
New to the forum and trying to find the answer to an ongoing problem with my 02 Grand Cherokee 4.0 six cylinder, maybe some of you have been down this road and can help me out.
The back story is...about a month ago the Jeep started chocking out while driving and engine eventually would quit running. once it cooled down it would start and run for awhile then act up again.

Had it towed to a mechanic three different times now. First diagnosis was a bad PCM unit, replaced it, Jeep ran fine for a couple days then same problem came back, mechanic thought maybe a bad unit so swapped out and installed a second one.
Same problem came back after a few days.

Mechanic said, must be the fuel pump. At that time Jeep had about 1/4 tank of fuel, I added enough to bring it up to half tank and car ran fine until it was down to about 1/4 tank then started choking out again so the fuel pump theory
sounded logical to me "but I am NO mechanic"

Did a fuel pressure test that registered 20 "while engine running", my understanding is 49 or higher is normal fuel pressure, so replaced fuel pump & filter with OEM parts.
Immediately new pump was whining like something was sucked up into it?? I asked mechanic if he drained the tank and cleaned it, he did not. Said it should run fine and he'd drop the tank when I ran the fuel down and clean it out and put in
another pump & filter.

Drove for about 30 miles and same problem, engine choking out while driving, limped the Jeep back home and am not convinced the pump or PCM unit is causing this issue. I read on this forum and other places that it could be the crank position sensor
but heard others says when the CPS goes bad the vehicle usually won't even start, mine starts fine Here are my novice observations.

**No problems at idle. I let it run in the driveway for over an hour multiple times, also no issue when revving engine.
** Problem only occurs while driving, doesn't seem to matter if engine is hot or cold.
** Once engine starts to choke out, I can get the car to a safe spot as long as I baby the throttle, once I step on the gas is when it violently starts choking out.

I would so greatly appreciate some feedback from anyone on this forum who has dealt with this problem, Throwing money and parts at the thing is getting old & expensive!

Bill.