zimbobwye

Hello all.
2000 XJ 4.0 218,000 miles.

Code thrown was for Cam position sensor failure. I know this can actually mean several different things. After removing the Camshaft Position Sensor, I found it in pieces, and the top of the Synchronizer(the rotor that spins through the sensor) was damaged.

Started like this. The other night, on my way to work, check engine light came on, but everything was running fine/smooth. The next morning, after -10 degree temps, it wouldn't start. I ran my battery down trying, attempted to jump, but still nothing. I left it for a few hours, and tried again when the temperature climbed into the positive. I got it to start right away on a jump, but it was running SUPER rough, as if firing out of order. I drove it that way, to the back of the building, where I was able to get it inside, and let it sit on a charger. Since then, I cannot get it to start.

Things I have already done/recently replaced:
My 4.0 has the coil packs, and those were replaced about 2 months ago, along with the spark plugs.

Crank Position Sensor was replaced 2 winters ago. (I'm not ruling anything out, but my Cam Sensor was clearly physically damaged. So, I'm starting there.)

Fuel Pump also, about 2 years ago.

I just attempted to replace the Cam Position Sensor, but realized that the top of the Synchronizer shaft seemed out of round, and had actually struck the old sensor, physically damaging it. I feel like this could still be because of the failed previous sensor.. improper firing caused the engine to run roughly, causing the shaft to move and damage the sensor?

Any thoughts? My next step is to attempt to replace the shaft, along with the new sensor. As I have attempted to start it since only replacing the sensor, it just doesn't sound right when it attempts to turn over. The engine is cranking, and it will backfire every once-in-a-while. I can smell gas when I flood the engine while trying to crank it over.

Sorry for the long post, I'm just explaining the story so far, and didn't want to leave anything out/have any questions left unanswered before asking for help. So, now, help, please?

Could initial sensor failure have caused the firing to be off enough, that the engine ran that bad, and further damaged the sensor?

What else could it be, that would not allow it to turn over at that point?

Any assistance would be greatly appreciated.


Thank you all.

CCKen

Failure of the Oil Pump Drive (OPD) and Camshaft Position Sensor (CMP) is not uncommon in the '00/'01 XJ's.

Unfortunately the helical cut splines on the camshaft may be damaged as well.

On occasion, the oil pump will freeze up and cause the OPD drive gear and cam gear to shell out.

Remove the OPD and, using a flashlight, look down in the mounting hole at the cam gear to see if it's okay. Use a flat bade screwdriver and turn the oil pump drive shaft to see if it turns freely.

If everything is okay, replace the OPD and the CMP.

The instructions are in your FSM. If you don't have a FSM, you can get a pdf version from Pacific Coast Manuals. com for $7.95.

zimbobwye

Thank you for the info. I will check it out when I get it apart.
I appreciate the response!