cherokeedave2000

My 2000 6 cyl. fuel injected 4.0 Cherokee ran perfect the night before, next morn, preparing for a trip to 6 flags with kids waiting, it would crank but not start, sprayed starter fluid into the butterfly when i turned it over it attempted to start so I'm getting spark. I turned it over while holding the needle open at the elector rail and a solid stream emitted so I'm getting fuel to the injector rail. Could it be that I'm not getting the Voltage pulse to my ejectors ? How do I test for this without a scope. Thanks for any info.
Dave

RHStorm11

I just solved a fuel problem myself ( see recent thread - Jeep won't start fuel pump won't run/stay running ). If you're getting spark and pumping fuel your cam and crank sensors should be working properly - but there is a reply on my thread on how to check the crank sensor.

Just b/c Fuel squirted out doesn't mean that there is enough pressure to properly run ( my 1999 GC died on me last winter and when I pulled the rails apart fuel was squirting too - unless you have a pressure gauge there is no way to tell for sure ). I would first check that all the relay's and fuses are good. After that I would relieve the system fuel pressure, and disconect the fuel line at the rail, put a clear plastic bottle on the end, and then turn the car to "on", a small amount of fuel should have been pumped into the bottle. After that, crank the engine, if the bottle fills w/ fuel then you know its not fuel related and can take that out of the equation. That narrows you down to air and spark. If it doesn't then you have to find out why the pump isn't getting power.

I really can't give any advice on checking injectors b/c I haven't had to do that, but after trudging around my fuel system and the wiring I have a pretty good understanding of that side of things.

I know its not the end all fix all answer, but I hope it gets you moving in the right direction...

Cheers!

seed

are we talking about a cherokee or grand cherokee?

cherokeedave2000

My jeep is a 2000 Grand Cherokee,thanks for replying guys

cherokeedave2000

Thanks for getting back, is there a control module that supplies the pulse train to the injectors

seed

http://wjjeeps.com/modules.htm

have you ruled out the simple stuff? Also wj's have a notorious fuel pump issue,if you turn the key to "on" position for a few seconds then try to start it,will it start?

cherokeedave2000

I just remembered how to check fault codes by turning key 3 times. It spit out code 0320 Crankshaft position sensor (CPS) I think I’m on the right track as this produces the pulse train to the PCM and injectors, purchased a new CPS from autozone for 60.00 along with replacement info. I was able to disconnect the connector from the left side of the eng. above the starter ohmed out pins B and C, should read infinite resistance mine read close to 0 ohms. HOWEVER, even though I have long arms I have big hands and can’t seem to find the nut let alone remove. If anyone has a method I would sure like to know, such as tools used, pics etc..or I’ll have to take it to a Dealer..OUCH Thanks

ol"blue

Check post #3 by 5-90 in this thread. It should help you.
https://www.cherokeeforum.com/f2/where-crank-sensor-my-jeep-18553/

seed

The CAMSHAFT position sensor is above the starter, do not take the single bolt out you will be removing the oil pump drive assembly. Your CRANKSHAFT position sensor is on your bellhousing,left rear.