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Tim Mohr
Category: Car
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1990 Jeep Cherokee: runs fine, holes fuel pressure..position sensor

Customer Question

1990 Jeep Cherokee 4.0 MPI, extremely long cranking time but will not start without ether once started runs fine, holes fuel pressure, have replaced following parts using salvage parts with no change in symptons: throttle body, map sensor, reman distributor, timing gear and chains are new, fuel pump, logic module, cracked fly wheel was replaced by transmission shop and supposedly crank shaft position sensor also changed. No fuel leaks, once engine starts, runs and accelerates fine. If it is shut off after running and try to restart immediately or later it will not start without aid. Is it possessed? How do we exorcise it?
Submitted: 8 years ago.
Category: Car
Expert:  Tim Mohr replied 8 years ago.
the older jeeps had problems with the crankshaft position sensor doing this exact same thing. If you dont know for sure it was replaced, i would put one in.
Tim Mohr and 5 other Car Specialists are ready to help you
Customer: replied 8 years ago.
where is it? There is not mention of this sensor in the service manual for this year model
Expert:  Tim Mohr replied 8 years ago.
It is on the top of the transmission bell housing. it is connect with two bolts, From the drivers side engine compartment, look to the rear of the motor behind the throttle boddy, you will see a pigtail connector that goes toward the rear of the car and then drops behind the manifold, follow this to the crank sensor
Customer: replied 8 years ago.
Thank you very much, we will go try it.
Customer: replied 8 years ago.
<p>Tim,</p><p> </p><p>The crank shaft positioni sensor is new. Any other ideas? The harness is plugged in.</p><p>DS</p>
Expert:  Tim Mohr replied 8 years ago.
next step would be to install a fuel pressure guage, prime the pump and turn off, If the pressure drops then i would suspect the fuel pressure regulator.
Customer: replied 8 years ago.
thanks, XXXXX XXXXX back to you. have one to try.DS
Expert:  Tim Mohr replied 8 years ago.
I see your 1st post said you used salvage parts, Was the crank sensor also salvage?