Dave_1972

I have a 1996 Cherokee with the 4.0 HO engine. I have been looking at a couple of problems.

1.) The engine has been running rough since I bought it - occasional miss that seems to get a bit worse when the engine heats up. But otherwise the engine had plenty of power, didn't run hot, oil pressure fine, etc.
2.) Several times now it has thrown a Cam Position Sensor error (code 54) after I have driven the Jeep until the engine was warm and then stopped the engine. Upon attempting to restart it would throw the code and fail to start.

As part of trying to work out the rough running issue I have cleaned numerous sensors, looked at vacuum hoses, etc -the usual stuff I could think of or run across via google. I replaced the coil, plug wires, distributor cap, and some other things I can't remember right at the moment - all to no effect.

As to the CPS issue - I have replaced it three times. Each time it fixes the issue for a short time and then it happens again.

Well, today the issue ramped up a bit.

While driving it to a friends place to do some floor pan repair - it started losing power. It took about 10 minutes but eventually it was barely pulling in 2nd gear and then died. After it died I was back to the good ol' #54 code. No new codes presented. I just get 12-54-55. 12 and 55 I understand are to be expected.

I am starting to suspect the PCM is the problem. Some threads I read indicate a malfunctioning PCM can burn out your CPS's. I have looked at some ways to repair the PCM yourself by re-soldering the board but I appear to have a different type of PCM than the one I see in the tutorials. Mine looks far more difficult to get open and work on. It looks like this:

http://carcomputerexchange.com/jeep/...FcHm7AodHWkAug

Has anyone tried to open one like this and resolder the connections on it?

Keeping in mind that this engine appears to have 250,000 miles on it.

I was also considering replacing the distributor because of the CPS codes.

Radi

You've replaced the crank sensor (on the bellhousing) 3X?

What do the PCM connectors and grounds look like? How about the CPS wiring and ground?

Dave_1972

I've replaced the Crankshaft Position Sensor once - the first time I replaced the Camshaft Position sensor - the camshaft sensor is the one inside the distributor. I've replaced it three times and that is what is still issuing the code 54. The wiring looks ok, but I haven't run it back the entire way through the harness.

The PCM connectors are a little beat up (cracks in the plastic) - this is a dedicated off-road rig and so it's seen a bit of abuse. But I cleaned them up and they seem to be connecting and staying tight.

RTorrez1

Where are you getting your sensors from. DON"T get after market from any parts store. Get an OEM sensor from the dealer. After market are garbage and rarely work.

Dave_1972

The first two were from "O'really's?" - after that I got a Napa Echlin. I am under the impression that they are of better quality.

Radi

Ever checked the supply voltage to those sensors? IIRC the sync sensor in the distributor has a violet/white wire that supplies 8 VDC from the PCM. The CPS is fed from that same supply, so a fault in one might affect the other.
You might also try heating the sensors and the PCM with a hair dryer, one at a time, to see if you can recreate the fault, since you said it happens after shutdown.(heat soak)