Two prong sensor. Located on the drivers side of the block. More towards the front of the block than the back. It screws into the block right above where the oil pan bolts down, then a electrical connector connects to it. I need to get whatever this is replaced now, along with the electrical part but I dont know what its called. Any help? Its a 89xj with the 4.0

I am almost positive that it is the crank position sensor.

Originally posted by norcalXJ
I am almost positive that it is the crank position sensor.


:laughing: Uh-no. I would think more along the lines of a knock sensor. The CPS is in the bellhousing on 4.0

I think it is the knock sensor also. I just went to the stealership cause no one else had it. It looks totally different than the one I had. I hope it work or I am going to have to buy all new wires and then I am going to be really mad. thanks for your help.

They changed the design of the Knock sensor to reduce breakage. That's why it looks different. The old style got broken too easily.

tell me about it. Mine did break. It was a POS. I replaced it with a new one today and my rig still wouldnt start. I am going to try to get a CPS by the end of this week but I think they are kind of expensive. I was at the junk yard the other day and they had two really clean looking XJs there. Would it be dumb to pull a CPS off one of those, or should I just go ahead and buy a new one?

I replaced mine and went with a Chyrsler one. They always go out. When it comes to electrical parts I like to use factory parts.

I would of replaced it before a knock sensor for a no run condition. Knock sensor will tell the computer to retard the timing a CPS tells the computer that the engine is turning and how fast.

Originally posted by norcalXJ
I am almost positive that it is the crank position sensor.

See, I was just telling him that the cps was the problem. Every one knows that he was talking about the knock sensor.:flipoff2: