Helping my buddy in the morning to diagnose a problem. He was Rollin down the highway and the xj just completely shut down and wouldn't start back up. Going into this one blind with only that info. Go with your suggestions! Thanks.

 

Crank Position Sensor comes to mind. Also check fuel pressure at the rail and make sure fuel pump didn't go out.

 

He said he has fuel pressure. Good call on cps

 

Do you know what year XJ is ?

 

I had the exact same thing happen last week! My cps got damaged. I have a picture, I'll try to load it. The new crank position sensor fixed the issue right away. There is a resistance and voltage test he can do on it, but mind you, these values are known to change with heat!

 

P.S. the bolts are special! They do keep the sensor at a specific distance from the tone ring. If they are wrong (the previous owner of my jeep ****ed me by being cheap on the bolts) are available from the dealer!

 

99 or 2000 I thnk

 

On my 97, the crank sensor and the cam sensor both died.

 

If you think you want to change the Crankshaft Position Sensor, get a MOPAR sensor from the dealer. After market parts often fail right out of the box.

OEM part number 56027866AC. Same part number for the 1999 and 2000-2001.

MSPR $75.60

Can be had cheaper on line.

http://www.wholesalemopar.com/parts_...FRJBDQod4Dr6oA

But it takes forever to receive the parts from these folks. Dealer; next day.

 

Same deal on my 98. CPS failed on the interstate and shut me down. Found that the coil had also gone as well as the CamPS on it's way out.

Cam/CkPS and Coil replacement should be part of preventative mntc for 4.0s with more than 150K miles....

JW