View Full Version : Just Turned Off

January 31st, 2006, 16:10
I'm reposting this to rephrase it. Today after running fine all morning the Jeep just turned off. Everything worked and it cranked over it was just dead. It sounded like when you crank the motor without the ignition turned on. After 30 minutes it fired right up. I did nothing but check all the PDC fuses. I'm scared now to take it out until I figure out what caused the problem as I don't want to get stranded. I'm thinking: vapor lock, auto shut down relay, ignition switch, or ??
Any thoughts?

January 31st, 2006, 16:12
That is classic CPS failure. It can be temperature dependant, cutting out when it gets hot. There are other possibilities, but CPS is the most likely.

January 31st, 2006, 17:00
What is a CPS?? All these initials are new to me.

January 31st, 2006, 17:50
OK, crankshaft position sensor. I went through all the possibles in the FSM index. Is that consensus guys? Gets hot, quits, cools off runs. I sure like my 69 CJ5 better and better. I can work on it!!
It looks like I need to buy a code reader if I'm going to work on this thing. It seems constant.

January 31st, 2006, 19:22
tgregg, i had the same problem with a 90 4cyl xj. once it was replaced(cps) it never gave me any more problems.i would say thats the culprit.

January 31st, 2006, 20:02
Almost certainly the crankshaft position sensor.

Mine crapped out on me a few years ago, at 70 mph in the center lane on I-94 southbound out of Milwaukee. No fun at all. Managed to get it to limp to within a few miles of home.

January 31st, 2006, 20:08
Thanks, a new one goes on tomorrow.

February 1st, 2006, 20:50
BTW, a bad CPS will generally not set an error code.

February 2nd, 2006, 05:11
OK, I changed it out yesterday. By the way the dealer charged me $136 for the sensor. Now I just wait nervously to see if it fixes the problem. Seems like it should but until I get it real HOT I won't be sure.