1998 jeep cherokee 4.0 aw4, 140,000
Starts up perfect, but it has idelling problems, it will be running just fine and then it will run like complete crap, it will drop to like 500 rpms, shake the whole jeep, giving it gas dosnt help but if you shut it off and restart it it will run fine again untill it does it again, seems to only do it once its warmed up.
Problem Number 2- On acceleration at about 15 mph it will studder and hesitate and pop from the intake, does this to 30 and it runs fine, does it the worst when the engine is cold or when its low on gas, but also does it at operating temp and with a full tank of gas.
It throws 02 sensor code, P138 Running rich
Iv replaced both o2 sensors, cps, tbs, computer, map,
Also performed Fuel pressure test and it was it spec,
Did compression test and it was also in spec
Vacume while ideling good is in spec but when it idels bad the vacume drops severly
Im getting like 9mpg in town and 12 highway
I have 32s and stock gears
Its been doing this for almost a year and i can not figure it out, im ready to push it off a cliff and stat over...:dunno:
Starts up perfect, but it has idelling problems, it will be running just fine and then it will run like complete crap, it will drop to like 500 rpms, shake the whole jeep, giving it gas dosnt help but if you shut it off and restart it it will run fine again untill it does it again, seems to only do it once its warmed up.
Problem Number 2- On acceleration at about 15 mph it will studder and hesitate and pop from the intake, does this to 30 and it runs fine, does it the worst when the engine is cold or when its low on gas, but also does it at operating temp and with a full tank of gas.
It throws 02 sensor code, P138 Running rich
Iv replaced both o2 sensors, cps, tbs, computer, map,
Also performed Fuel pressure test and it was it spec,
Did compression test and it was also in spec
Vacume while ideling good is in spec but when it idels bad the vacume drops severly
Im getting like 9mpg in town and 12 highway
I have 32s and stock gears
Its been doing this for almost a year and i can not figure it out, im ready to push it off a cliff and stat over...:dunno: