The wifes 2004 grand cherokee laredo 4.0 died on the way home today... And of coarse i am out of town. She said while driving it just shut off and she coasted to the curb. It cranks over great but wont start. Any suggestions on what i should start checking when i get home in the morning? It was running great up to this point.
X2 :thumbsup:- Had the same symptoms, be running fine then just die like someone turned the key and shut it off. Would crank over real strong but no start. Changed the Crank sensor with a dealer replacement and all is good again, got my fingers crossed ofcourse.
take the cap of the valve on the fuel rail turn the key press it in or hook a fuel pressure gauge up to it.
also listen for the pump to prime up. but turning pressing int he shrader valve ( tire valve looking thing) you should get STEADY stream of gas if the pump is working.
Ok so TURN key to ON
pop hood
Unscrew black tire cap looking thing Attach either a fuel pressure gauge to it. or press the valve in mine gave a great squirt then it just trickled out after that i believe fuel psi should be 40 when just primed and 40-45 when running.
ok we narrowed it down i got fuel but my 15 amp injector (#26) fuse keeps blowing everytime i turn the key it runs for a bit and then blows.... uh oh this aint good
had it running for an hour and it was fine. Then took it out later and hit some big bumps and the fuel injector fuse near battery keeps blowing. Obviously it's a dead short.... Any ideas of where to start looking for shorts?
Some people may say to just use a bigger fuse... I'm not a Jeep guy, but I know my way around cars and troubleshooting. This would be easier if you had a wiring diagram or schematic out of a service manual. Otherwise, since it's JUST the injector fuse, I'd start either at that fuse and work your way towards the injectors, or the other way around. Tracing electrical faults are a PAIN.
Take a general look around your engine bay and battery area. Make sure any obvious grounding spots are taken care of. I'm not familiar with the GC, any bad spots for wires wearing through under the interior carpets or panels?
I think i found the problem. I had a remote starter installed and they soldered a wire to one of the fuel injector wires. I totally disconnected the remote unit installed new fuses and it started. I am gonna run it for a few days,hopefully this was my problem.
Well, it wasn't the remote starter... I disconnected it and for about a week it was fine but now its still blowing fuel injector fuse. Does anybody know if problems with the coil pack would make the fuse blow?
That would have been the obvious culprit... The coilpack shouldn't come anywhere close to interfacing with the fuel injector electronics. Much too high a voltage involved... Perhaps you jostled something when you first disconnected the remote starter that has now fallen back into (out of?) place?
Could there be a short in the ECM/PCM that can be tripping the fuel injector fuse? Whats really weird about it is after pushing it home (again) i put 2 new fuses and it blew both of them then on the third fuse it started right up and has been running for 2 days now. There is no reasoning behind this because its blowing fuses whenever it wants to.
What i did so far is change coil pack,cam position sensor,crank position sensor,new spark plugs and put a new ground to the motor. Hopefully one of these things will fix the problem. Its my wifes vehicle and i can't afford for it to keep breaking down. lol
Does anybody know if i was supposed to remove the little felt piece off the end of the crank position sensor? The reason i ask is because its been running good for a few days and all of a sudden it threw a P1391 code today. (Intermittent loss of CMP or CKP signal).
Felt tip only there for proper spacing.If you used OEM(dealership)sensor, shouldn't matter. My OEM sensor came with round bolthole and not adjustable. Aftermarket sensors I noticed have oblong holes, where you would need it for proper spacing.
Ok thanks... So if i installed it all the way in it spaces itself ... b/c i had the oblong slots for bolt? What the h*** triggered the p1391 code now? The sensor that i took out had a tiny piece of the felt left on it. It looked like it pulled or ripped off.
Hate to say it, but inserting it without the spacer AND the oblong bolthole might of damaged it. Spacer needed more with oblong bolthole, it sets the proper depth of sensor. Spacer is designed to come off when the engine started for 1st time after install.
Ok thanks. I left the spacer on and pushed it all the way in when i installed it and then tightened it up. Maybe the spacer came off and interupted the circuit for a second or two. I will clear the code (P1391) and run it for a few days to see what happens.
Crank or Cam position sensor and both will throw a code. My old intrepid did the Cam sensor on me It ran PERFECT and we parked it for the night, it would not and I mean WOULD NOT start the next day. So for sure run the scanner on it it will almost certainly give a code for whatever happened but I'd say it's probably a sensor.
****EDIT****** HA HA OOOPS Clearly this one is pretty much solved.. way to go me..
I am currently having the exact same thing happening with my 00 wj. Please let me know if you found a solution.
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