00' XJ no start

whitneyj

whitneyj

Well-Known Member
Joined
Apr 30, 2008
Location
Mayville, WI
Searched and troublshot according to everything I could find and I can't seem to figure out the issue:

The Jeep turns over, but won't start. Zero voltage to fuel pump, but getting 11V at the fuel level sender. Fuel pump relay is good. ASD relay is good. Ohm'ed the CPS and it's the same as a new one. Swapped my spare PCM and no change. Grounds are all on fresh bare metal.

Anyone have any ideas?
 
No clue, I'll check that when I get home. What's the range it should fall under?
 
IIRC it should be approx .5-1.0 v AC. Basically, see if it is generating any voltage while cranking., if not, the sensor is bad.
 
whitneyj said:
Zero voltage to fuel pump, but getting 11V at the fuel level sender.

Anyone have any ideas?
Click to expand...

hear the pump run when turning key to on position? if not check the O2 sensor wire to make sure it didn't get burnt against the manifold. check fuses for the one for the pump in the PDC, its one of the larger fuses (assuming its set up similarly to a older(93-94) xj)
 
a_kelley said:
hear the pump run when turning key to on position? if not check the O2 sensor wire to make sure it didn't get burnt against the manifold. check fuses for the one for the pump in the PDC, its one of the larger fuses (assuming its set up similarly to a older(93-94) xj)
Click to expand...

Zero voltage to the fuel pump-all the time. It doesn't do the 3-5 second priming. O2 sensors are all good. How do the O2 sensors affect the fuel pump getting voltage?
 
Jody Treadway said:
IIRC it should be approx .5-1.0 v AC. Basically, see if it is generating any voltage while cranking., if not, the sensor is bad.
Click to expand...

Incredible info! Thank you. I'll have to check again, I didn't realize it was supposed to be that low, but if I remember correctly it was less the 1 VAC
 
I guess I didn't ask which pins I should test power from. I tested pins B and C-the ones I ohm checked per manual-and came out with 0 VAC's. The 3rd pin-anyone know what that's for? Is that just a signal from the PCM? Or is that something I should test with one of the other 2 pins?
 
I tested for VAC on pin B and C and came to 0 volts.

The camshaft positioning sensor looks good. It's tight and the wires are good. I peeled back the wire loom to take a look at any potential chafe points and there's nothing.

I'm leaning towards the CPS. Anyone have any other ideas before I replace a $90 sensor?

Crankshaft positioning sensor put out 0 VAC. Going to replace that tomorrow unless someone pipes up
 
Replaced the CPS and no change. The old sensor's magnetism was also significantly stronger than the new sensor. Not sure if that's important or not.
 
Put power to the fuel pump and the pump itself is good. I let the fuel pump prime the system by jumping it with a separate battery and it fired and sputtered until the fuel pressure died.
 
whitneyj said:
Put power to the fuel pump and the pump itself is good. I let the fuel pump prime the system by jumping it with a separate battery and it fired and sputtered until the fuel pressure died.
Click to expand...
random thoughts here...fuel filter clogged?
FP regulator not regulating properly?...no idea how to check this.
 
try ....

no clogged fuel filter will not be the problem as if he jumps the pump it will some what start. you have the get a diagram. if your unable to find one to trace hit me up dougmakar@gmail.com ill get ahold of one for yea.
 
I have the schematics and figured at least something out. I now have 12V from the relay to the pump, but no ground. The PCM closes a common ground. I ran my own ground to bypass the PCM and it runs like a champ. I'm not sure why the ground isn't being closed.
 
RenegadeT said:
random thoughts here...fuel filter clogged?
FP regulator not regulating properly?...no idea how to check this.
Click to expand...

Neither of these 2 control power being sent to the fuel pump. If the fuel pump was receiving 12V, was whining, but I still have zero or low fuel pressure, then I'd target those 2 ideas you had. Thanks though.
 
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