Big Blue xj

Ok so here's the deal I have a 95 Cherokee xj it all started one day out of nowhere my jeep started running really rough and my check engine light came on I checked the codes and there was several diff ones , the next day goin down the road it lost all lights inside and out , a couple min later it completely dies and batt is dead I have someone bring a batt put it on starts up drives fine so I have mine checked its dead so I replace it jeep runs great for 3 or 4 days then starts the same missing and check engine code but this its the code for a bad alternator so I take it off and have it checked and it passed but I bought a new one anyways put it on jeep ran great for a week until I took it to the trails and it started it again so a friend said it sounded like the idle control sensor and he had an extra new one so I installed it and low n behold my jeep was running perfect the whole day and for two weeks but here we are again wither same problem part time crappy running and check engine light with several codes ... somebody please help I'm thinkin its the ecu . Any suggestions will be greatly appreciated

spazzyfry123

Man, that was one hell of a sentence!

Is your alternator full of muck?

Big Blue xj

No it is brand new and now my jeep will not start at all just turns over and I'm getting no fire or fuel and my yacht is bouncing back and forth with the key in the on position and the check engine light doesn't work at all anymore not when u check it or turn the car switch on

spazzyfry123

No spark AND no fuel? What is a "yacht"? (besides the obvious: boat)

Why couldn't you just have a '96 with OBDII?

fishtaconc

Wow... a XJ on a yacht, probably too much salt air has corroded something. LOL j/k... Have tested the Crank. Position Sensor, that is the number one culprit to a no fire situation, many,many threads on how to test that particular sensor. Start there report back. Also inspect fuses, make sure none are blown, if any are, look for a short somewhere.

spazzyfry123

CPS is my guess so far as well.

Big Blue xj

The rpm gauge bounces and I have checked all fuses and relays .but I was literally lookin at the motor running and it just died like someone turned the key off and will not start back up it lost fuel and fire at the same time and now the check engine light will not respond at all

fishtaconc

IIRC, if the CPS is not functioning correctly, it will not fire the injectors, it is a known fact that it will not trigger a spark.

Big Blue xj

So are you saying it sounds like a bad computer ? And is there any way to check it short of buying a new one ? And thanks for all the info guys

fishtaconc

Not at all. The Crankshaft Position Sensor, is a likely culprit, its located on the drivers side on the bellhousing. It will need to be tested to rule out other possibilities

Big Blue xj

But would that make me lose fuel and fire? I straight wired the fuel pump and it works fine just won't work w tvhe key on

Big Blue xj

How do I check the csps

Jeffvador

I am having the same problem right now with my 87 xj. Did you ever discover the problem?

freegdr

renix era xjs are very picky about there ground wire connections i would clean and reattach those first see what happens

Jeffvador

alright thanks, I'll do that in the morning