apagan1990

Hey All,

Short story, girlfriend bought an XJ. Three weeks later it starts and makes it 1/4 mile before dieing at a light. It will crank and crank but not start.

-No fuel pressure, tested with meter
-Gauge reads empty but will do a full sweep if I hold mile reset at power up.
-Put in a new fuel pump just now and same condition exists
-Swapped relay with one of the others that had the same part number, no change
-Disconnected the Crankshaft position sensor and the fuel gauge still reads empty. (read a thread saying that if it began to show a reading this is culprit)
-Sprayed starting fluid in and it sounded like it was firing but these intake manifolds arent really a great shape for getting a good spray in there.
(Spark seems ok)
-Cooling fan runs on powerup now which is new IIRC.

Any advice? yes I am searching lots but honestly cant afford to miss another day of work fixing this. She has the next 4 days off so I have a window to make some progress. Reading makes me still think Crankshaft sensor but that thing is burried deep on these 2001's

Any help is appreciated, I know we have all been here before.

wizardpc

It is easy to test the cps, and there is a fairly easily accessible connector for it in the engine bay. The number one reason a 4.0 will crank and crank and crank but not start is a bad cps.

https://www.cherokeeforum.com/f51/testing-cps-5563/

The fuel gauge issue is likely separate.

zjhomme

well you could try a new girl friend,but seriously check all and i mean all your fuses.had a similar sounding issue with a 96 xj.and yes the cps is a bear to replace.i did it before i found the real problem.

apagan1990

Well, Have thrown a fuel pump and now a CPS in the thing and still no start. I am running out of things to throw at it lol. Only thing I forgot to mention is it says "no Bus" on the mileage readout when cranking. any ideas? I'm getting the feeling im going to have to chase a magical electronics fairy through this thing.

wizardpc

That was a fairly critical piece of information

https://www.cherokeeforum.com/f2/no-bus-no-start-84545/

You had the no bus before you replaced the cps, and now you still have it?

apagan1990

That is correct, I had it both before and after replacing the CPS. It does not display "no bus" constantly though, seems to be only after cranking and when it died.

After some reading I may begin to chase down ASD problems as well. Given that the CPS has been changed I should also test that whole circuit for shorts. Seems that the ASD "system" could also prevent me from getting power to the fuel pump.

Somewhat related, I swapped the fuel pump and starter relays, still cranked so at least it wasnt a broken relay. Still could be a wiring issue though. I'll post back with any findings. At least this will be an interesting one.

Roler

Please tell me you checked fuel in tank...died out of the blue, gauge reads empty, cranking but not starting.... (besides a no bus).

apagan1990

Turns out I was out of fuel.... Kidding.
but the truth is no less painful.

OK so we replaced the fuel pump and CPS. Still no start, we were going to check the ASD circuit but decided to CHECK EVERY SINGLE FUSE first.... In the engine bay fuse box, the mini fuses, there is a lone line of four fuses within the cluster of mini fuses, these are separated by an obvious gap. One of those 15amp fuses was blown. A diagram had it labeled as the fuel pump pcm fuse.

It fired on the second run of cranking after it got fuel back.

I may bench test the old fuel pump just to verify that the whole problem has been solved, and will be driving close to home of course.

Rule one check ALL fuses.

I appreciate you guys taking the time to help out.