2000grnxj

Recently got a 2000 4.0 xj, did some preventative maintenance new thermostat, flushed the radiator and heater core, new exhaust, new battery, new pcv valve, ect. Was running good, drove down the road last night and probly after 20 minutes it just died going down the road. Cut it back on it would run fine for 30 feet or so then idled rough and then cut off, let it sit a few minutes it would start back go another 30 feet or so then idle rough and die again check engine light would come on and off. Took a hour to go 2 miles. Ive heard it could be the throttle position sensor or crankshaft position sensor. Any thoughts ? Just hit 152k miles,

papablista

Sounds like either a clogged fuel filter or pump going out .

2000grnxj

I think i may have got water into something when i was flushing the radiator. Its sat over night gona check all electric connections today for moisture

PatHenry

You might want to scan the codes, even if the light didn't stay on you could have some information in there that will help.

I'd start with the requisite grounds and battery cable cleaning. Then do a fuel pressure test.

I can't think of anything where water might have gotten in during a radiator flush that would cause it to die like that.

mattheww97

Rent a fuel pressure test kit before you start throwing parts at it. There is a possibility that it is your crank sensor or TPS but in my experience, when those parts go bad, the Jeep stalls with no rhyme or reason. Yours seems pretty consistent. I would bet its a bad fuel pump. Rent the test kit and test the pressure at the fuel rail .

BillyBoy

X2! Its FREE!

PatHenry

Even if you don't have a good loaner tool option available, it's still not too bad to grab a test gauge from Harbor Freight (~$20).

2000grnxj

Worse that i was wishing for. Low compression in 4 cylinders

gat

Were the four cylinders in adjoining pairs? That could mean that the gasket is blown between them as opposed to wear at the valves, rings, pistons, or cylinders.

A borescope(/videoscope/inspection camera) would allow you to look for scoring thru the hole for the spark plugs. If it was only four of six, then I wouldn't imagine it to be timing as the issue.

2000grnxj

Im taring it down this week. Its 2nd thru 5th cylinder low compression

gat

It is a bit daunting, but certainly achievable task. Punching holes into boxes and inserting the bolts, rods, and lifters really helped me several weeks ago. It was so cold and wet that I didn't get to do it on the same day nor consecutive days.