Hey guys, I'm Adam, I'm new to the site and while Searching for info on why my 2000 Jeep XJ is acting the way it does, the web led me here. I must say, NIICE site.. Lots of info here!!
I bought my 2000 XJ about 6 months ago for $700 with 170,xxx miles on it... Been running it ever since. So far ive only had to change the waterpump and belt. Anywho, about a month ago, while riding around town, it started acting funny, "skipping/sputtering", then it died and wouldnt start.. It sat for a few hours and fired right up. Its been doing it ever since and getting worse. It'll go for a few miles then it starts "bucking" and eventually dies.. I only work a couple miles from home, so i figured i could get back and forth for awhile until i could afford to fix it. WELL, That time has come. After reading around a bit and talking with some people, i came up with................ A bad(or going bad) fuel pump?!?!........ I picked up a brand new one today for $100. and NOO its not an AIRTEX, its a BOSCH!!!!! LOL. I plan on swapping this little thing in tomorrow and seeing if that fixes the problem.. Which I really hope it does, because i need to get this thing off road and back in some mud..

 

you got a deal on that xj mine is an 200 with 180k and cost me 3 grand. id do the fuel filter too if i were you though

 

1. Be sure you have fresh plugs. A good choice for yours are NGK copper plugs; be sure they are gapped to 035.

2. Have you seen any check engine light? If so, you MUST retrieve codes.

3. The fuel pump may or may not be the root cause. The best thing to do when you suspect a fuel delivery problem is to verify fuel pressure. For yours, you should have 49 psi, plus or minus 5 psi. Did you do that? Otherwise, it's hit and miss throwing parts at it.

4. Did you buy the entire fuel pump ASSEMBLY, or did you buy just the fuel pump. I always recommend replacing the entire assembly while you have the gas tank done. I don't like doing things twice. The filter and regulator are all included if you purchased the "assembly".

 

I havent scanned it , YET...... I plan on having that done tomorrow just before the fuel pump install. also, i did plan on checking the fuel pressure prior to install as well... Fuel pump just seemed likely, from everything ive read... Another thing, i am not sure on how recent the plugs were done. I guess i should have started there, but kind of got pressured into changing the pump first.. I am a chevy guy, this is my first vehicle that wasnt chevy.. Ive talked to a few peeps who have had nothing but jeeps, and has a few of them still and from the symptoms ive described, they strongly believe the fuel pump is at fault... We'll see

 

Fuel pump eh? I was thinking of some sort of sensor or vacuum problem. As mentioned check the codes asap

 

check your fuel injectors. you might just have a leaky one.
with the engine running, twist each injector to see if the idle changes.

 

I'd say it's a good guess. Good idea to check your FP before changing so you know for sure if it's the problem.

 

Autozone has a fuel pressure gauge that you can use (you buy it at the ridiculous price of 150$ but return it at full warranty).

My jeep was actually doing the same thing. Checked the fuel pressure at the rail and it was way under, and checked it at the fuel pump and it was way under. Right now I'm soaking my tank in detergent to clean it once and for all. This makes fuel pump number 3 for me... The bosch one is pretty good from what I can tell except that it failed due to a bit of dirt ...

Napa is very lenient with me and has replaced it each time it has gone bad. Of course, each time it has nearly left me stranded in the hills, miles and miles from home....

 

What about the crank position sensor. Those seem to be a common problem with the XJs.

 

From my experiences with a bad CPS. It doesn't make it "skipping/sputtering" It normally just cut out. Like I said that is only my experiences with bad CPS's. It does sound more like a fuel problem.

 

Sure sounds like the fuel pump to me. When they start to go bad, they sometimes seem to work fine until they've been running for a while, then it just gets worse and worse - either they're overheating (which is a stretch because they're kept cool by the gas in the tank - have you run it out of gas before?), or sediment in the tank has finally taken it's toll and all of the little check valves and everything are so gummed up that eventually, during a drive, the passages constrict completely and block fuel flow.

Beating on the tank to vibrate the pump will sometimes loosen up the passages and allow the pump to work again.

 

ok, im baaack...... I scanned it before i swapped the fuel pump. Came back with only two codes.. a bad cam position sensor and a bad 02 sensor( bank 1, sensor 1).... Sooo, i returned the fuel pump and bought the CPS, changed it, no luck..... Went ahead and bought the fuel pump again, installed that, also did a new ($100) fuel filter as well..... Still no luck, its still doing it... Drove to work today and on the way there it started doing it again, bucking, Tach was going crazy(jumping all over the place) etc..... Scanned it again when i got there, and got a few more codes i hadnt gotten before.. First was, P1491 - manufacture auxilary emission control, second one was P1591 - control ignition system or mis-fire , third was, P0131 - o2 sensor bank 1 sensor 1, fourth was, P0136 - o2 sensor bank 1 sensor 2 and last but not least was, P0705 - Transmission range sensor circuit malfunction (PRNDL input) ... I'm thinking coil packs?? Any input will be greatly appreciated

 

Catalytic Converter?

 

What is your battery voltage? What do the cables and connectors look like, including engine and chassis grounds?

Looks like you are getting codes for everything under the sun, lol. I'm wondering if the problem is something more basic...like bad connections/ground/battery? Connector to the PCM clean and tight?

 

What about that bad cam position sensor code you got originally?