Scooter686977

My Cherokee has recently started sputtering a couple times a day....loss of power on take off and hiccupping through intake. It has less than 6,000 miles on a rebuilt engine (4.0) and a full tune up. I've checked the fuel pressure twice, 50 with key on and 47 while running. No change in pressure under load. Cap and rotor looks fine. All grounds are fine. Disconnected battery for a few hours. Still sputtering. One mechanic tried checking my tranny problem with his new snap-on scanner which kept rebooting while plugged into my vehicle. I've been told that the problem could be the PCU. Is this true? If so, where can I buy a new one and is there anything special about changing it out?

Dr J

bump.
and .. maybe one day a week my 96 GC sputters and dies at 25 mph in the neighborhood when first driving (less than a mile), before reaching operating temp. After that, not an issue at all. Mechanic said he read these models were bad to have a short in the guage cluster, and so might replace. Surely there might be something else. Anybody got any ideas?

dave1123

When you installed the rebuilt motor, did you install a new crankshaft position sensor (CPS)? I've been told your symptoms are related to failure of the CPS.

Griffin13

My 94 does something similar... As I drive I can see my RPMs fluctuating ever so slightly but it is noticeable and you can hear it in my exhaust, wondering if this is the same issue you are having

dave1123

Yours is most likely the TPS (throttle position sensor). Also check the hose to the MAP sensor. Try cleaning the TPS and throttle body.

mcdonaldanthony

PCM it's always the PCM in these crappy trucks, don't get me wrong I love them but tired of the problems

dave1123

Yeah, Jeep has a reputation for bad solder joints in the PCM.

1ATony

^^^^^YUUUUUP!...lol My TPS was bad for a year and didn't know it. My ZJ would hesitate once and a while on hot days.

Two weeks ago I was heading to work, and it went all together. It was like driving a buckin Bronco...lol

A bad TPS will make your Jeep hesitate and skip. I tossed one in during my lunch break over here, and my ZJ drives like it's breand new again. Made a huge difference.

See if you can get a code out of the computer. We carry TPS's for ZJs if you need one.

Here's a link to them. Jeep Grand Cherokee Throttle Position Sensor TPS

Griffin13

I have two codes showing up just no way to tell what they are. I did the turn key and count blinks method... I did take a look at your TPS and looks like your sold out for the one I need

Scooter686977

I changed the TPS and the PCM with no luck It turned out to be the 02 sensors......front and rear. Thanks everyone for you input.

dave1123

Now that's funny. I've been told by several mechanics, when you have a performance problem you just can't find, change the 02 sensor. My 97 ZJ would stumble after cold startup and pulling out of the driveway in the morning but was fine after about 50 yards. It was the 02 sensor.