joe28910

This is my wife's vehicle (97 Cherokee Sport 4.0l a/t). It ran fine one day, then the next would crank but not start. I could not get the fuel pump to run (gauges also dead) so checked all fuses and swapped relays without success. I jumped the relay and still nothing. I just finished installing a new fuel pump and still won't start (though getting weak pressure at fuel rail). I can now turn the pump on by jumping the relay, but with relay in place it won't kick on and gauges still dead. (again I swapped relays just in case one was bad and still nothing)

It seems to me that something is not allowing the relay to trigger the pump.

*can the crankshaft position sensor if bad cause this?
*can I test the CPS?

Any help will be vary much appreciated!!!

andrewnp

This is typical signs of the CPS going bad. Try unplugging it and if your gauges come back and it cranks up then it is definitely it, also if you have a fluke or multimeter around you can take a few resistances on the sensor, I can't remember off the top of my head what they are but you can look online or just head over to the auto parts store and take them on a new one and compare.

The swap isn't bad, just a knuckle buster. I used a 3/8" drive and some extenders, and a pivoting head. 11mm if I am not mistaken.

tjwalker

Classic symptoms of a failing crank sensor. They can be tested, but testing isn't always conclusive.

If you buy one, buy it directly from Jeep. Go directly past aftermarket for this one. There are plenty of us that have had issues with aftermarket. And considering the crank sensor is the most important sensor on your 4.0 engine, this is money well spent.