jeep sputtering

i bought a 95 jeep gc limited 2wd 4.0liter with 108k miles on it about 2 months ago... the night i bought it it started sputtering. when we test drove the jeep at the dealship on two seperate occasions it drove flawlessly. we at first thought it was just bad gas, so we ran it COMPLETLY out of gas and put more in and it still sputtered. then we did a complete "revitalizing" flush of every fluid in the car at city garage and a changed the plugs/wires, but it still sputtered. after the first 15-20 minuits of sputtering and being crazy it drives fine, but does seem to lag when shifting gears every now and then, and the catalytic convert rattles and is probly clogged. So we think the sputtering is something fuel related, or maybe an oxygen sensor, or maybe even something to do with the cat.. any info, advice, or suggestions would be GREATLY appreaciated.

,josh

up date... we replaced the oxygen sensor, and its still sputtering. we also replaced the cat.. the o2 sensor we bought is for a 96 though and the plug end is different, but it has the same wires as the stock one. so i just spliced the wires together according how the Haynes Manual told me to. so that brings my list of this replaced to Fuel pump, Cat, and o2 sensor, and a complete tune up and fluid flush :banghead: . i guess ill replace the fuel filter next...wish someone would reply to my thead..

hummmmm..

Sputtering is often related to a bad CPS (CrankShaft Position Sensor).

Remember to disconnect your battery before replacing any electrical parts on you jeep.

fuel pump

I would say after reading this, fuel filter. that was not mentioned. i would try that. I think that would be it. It right behind the rear dirverside wheel.

i bought a 95 jeep gc limited 2wd 4.0liter with 108k miles on it about 2 months ago... the night i bought it it started sputtering. when we test drove the jeep at the dealship on two seperate occasions it drove flawlessly. we at first thought it was just bad gas, so we ran it COMPLETLY out of gas and put more in and it still sputtered. then we did a complete "revitalizing" flush of every fluid in the car at city garage and a changed the plugs/wires, but it still sputtered. after the first 15-20 minuits of sputtering and being crazy it drives fine, but does seem to lag when shifting gears every now and then, and the catalytic convert rattles and is probly clogged. So we think the sputtering is something fuel related, or maybe an oxygen sensor, or maybe even something to do with the cat.. any info, advice, or suggestions would be GREATLY appreaciated.

,josh

What was the resolution for your problem , I have the same issues.
Thanks!

Same type issues 1997 Grand Cherokee, 5.2L, 187000 mi. Just bought it 3 weeks ago. Ran great on test drive, little more money than I wanted to spend, but went back 3 days later, another drive and bought it. Week later starts sputtering, check engine light came on. I go through the service records and it has had a pre-cat oyxgen sensor less than year old. Trouble code is downstream sensor etc. Replace post converter sensor, and while I'm working on it, tune up (plugs, wires, cap, rotor). Light will still come on and sputtering / low idle (only stalled out once), and when I try to get some power / speed for an onramp or something, RPM's will drop to almost nothing, very little intermittent response to throttle, I will hold throttle @ 1/2 and it will eventually kick in? Have replaced IAC sensor, cleaned throttle body. MAP & Throttle Position sensor test within spec (via Haynes). Replaced pre converter O2 sensor (held on to old one). Trouble codes still receiving are P0138 & P0132, both codes O2 sensor related, both are "shorted to voltage". I unplug front sensor and it runs great (obviously mpg's go way down), throttle response is immediate and constant continuosly, received exact same codes w/ sensor electrically "out of loop". There appears to be no cracking in the wires, connectors appear clean.

Truck would have symptoms at operating temp and less occasionally when cold. Both wet & dry weather. Now I thought fuel pump or possibly a plugged cat, but once front plug is disconnected electrically, yada yada yada runs great. The Auto shutdown Relay, if that was shot, would jeep even start / would it die at start up? I appreciate you reading this novel of mine, but it has me flabbergasted: I didn't pay much attention in electrical class, dealer wants a small fortune to trace this problem, and I've had a couple beers tonight. Thanks

I have only had sputtering 2 diferent times with my 98 grand cherokee. The first time was the TPS. It affected gas mileage, shift points, etc... The second was the fuel pump wearing out. But you guys have already tried those. I believe the only fuel filter aside from the mesh screens on the pump assy is integrated with (what, a regulator of sorts?? whatever, it's in front of the tank...) I don't have much to offer, but if you are not sure about the wires from the o2 sensor then find the other end and check your resistance to a ground point (frame). It should be read an infinant amount of ohms. Isolate the wires on both ends and measure between them as well. I am just trying to rule out reasons why you keep getting fail codes for the sensors even after replacing them. Would almost have to be a shorted or grounded wire. Do the codes automatically reset once you read them, or are you getting the same fault code? Keep us informed.

Do the codes automatically reset once you read them, or are you getting the same fault code? Keep us informed.

Codes do not reset once I read them

Generic scan tool to erase code. Generally same 2 fault codes trip engine light, may have 1 "pending" code, but always O2 sensor related. Going to start tracing wires. Will let you know if I find anything.
Thanks

I fixed my 2000 4.0 that had the same problem by changing the fuel filter/pressure regulator assembly. It should be located forward of your tank by the driver side wheel. If it's the regulator and filter combined like on the 99-up, it will have 3 lines attached. Be sure to relieve pressure in the system before dissasambly. Also have some paper towel handy cause if your assy is screwed up, you could still have some residual press on the lines.

LMK what kind of assy you have cause the return line can be a pain!

I fixed my 2000 4.0 that had the same problem by changing the fuel filter/pressure regulator assembly. It should be located forward of your tank by the driver side wheel. If it's the regulator and filter combined like on the 99-up, it will have 3 lines attached. Be sure to relieve pressure in the system before dissasambly. Also have some paper towel handy cause if your assy is screwed up, you could still have some residual press on the lines.

LMK what kind of assy you have cause the return line can be a pain!
hey with that assy did you have to go to the dealer and pay 100 bucks or did you find it somewhere else. i want to replace mine but don't want to pay that much

i had the exact same problem, fuel filter.

it ran hard when i started it but as fuel would run through the filter, it ran ok, because the crap in the filter was all stirred up.

i would honestly try that next

For those who asked i paid approx $40 dollars at autozone for the filter/ regulator assy. BTW it's on a 2000 4.0

pencapchew
"Light will still come on and sputtering / low idle (only stalled out once), and when I try to get some power / speed for an onramp or something, RPM's will drop to almost nothing, very little intermittent response to throttle, I will hold throttle @ 1/2 and it will eventually kick in? Have replaced IAC sensor, cleaned throttle body. MAP & Throttle Position sensor test within spec (via Haynes). Replaced pre converter O2 sensor (held on to old one). Trouble codes still receiving are P0138 & P0132, both codes O2 sensor related, both are "shorted to voltage". I unplug front sensor and it runs great (obviously mpg's go way down), throttle response is immediate and constant continuosly, received exact same codes w/ sensor electrically "out of loop". There appears to be no cracking in the wires, connectors appear clean."


Hey i seem to have the same type of issue, Im only getting the P0132 code shorted to voltage, the 02 sensor looks ok and the reading on the exhaust read good. i havent replaced it because of this, what was your cure? are my wires bad somewhere else that i cant see? and occationally i will start it up and it will run for a while with no check engine light on, but eventually it somes on and stays on..its a hard code mainly