genedog

Hello everyone, new to the forum, need some help please.

History: Just purchased a 96 xj cherokee.. 106k miles, 2.5 lift, Body is mint and Truck RAN great for 2 weeks.. until

Present: 3 days ago I pulled into my driveway, next day truck will not turn over...

List of what has been replaced:
Battery
Battery Terminals
Relay's
Starter
Distributor Cap
Ignition Coil
and the ever popular CrankShaft Position Sensor!!!!

Things i have noticed: NO spark from coil & I do not hear the Fuel pump humming (it is supposed to make a sound right?)

I know i changed A - Lot of things but i made sure that everything i changed was put back the way it's supposed to be.. I even took pictures to make sure.

I am completely stumped.. is there anthing i can check or recheck.. I have a voltmeter but not sure what voltage goes to what or what i am supposed to check for..

Cherokee Guru's Unite...

Any help is appreciated.

nick_n_ii

I'd say more than likely it's a crank position sensor..

They seem to just die out of the blue...

Every 4.0L I've owned has had one go out for no reason at all...

genedog

That's exactly what i thought as well.. I purchased a NEW one from PepBoys (62.00) and put it in.. Still NO start....

IS there something i need to do to after installing the CPS, I don't know maybe like a system reset or something? I mean I put the CPS in and put the negative cable back on the battery and turned the key..

I hope that the part did not come defective from PepBoys...

HockeyFan

If its not turning over at all check the neutral safety switch.

nick_n_ii

I was just thinking this very thing..

I missed the not cranking thing first few times through...

ET JEEP

Yes, you need to clarify whether the engine is turning over with the starter and not starting or if the starter does not turn the engine over.

If the engine is NOT turning over with the starter, it may be the neutral start switch. Try running your transmission shifter thru all the gears and try starting in park or neutral. If no engine turning over, check for voltage at the starter solenoid, with ignition switch in start position. You will need a helper for this. You should read battery voltage at the solenoid. The solenoid terminal is the small terminal. Also check for battery voltage at the starter terminal that connects the red wire from the battery.

If engine is turning over but not starting, check your ASD relay. Also check your fuel pump relay. Both must be good for engine start.

genedog

Thank you for the advice.. I apologize for not being clear..

The engine is turning over with the starter and I swapped relays around since they all had the same part numbers and still nothing..

Would this have anything to do with the PCM? would a reset do anything to help?

IF needed i can post a video of the truck trying to turn on, if that would help.. and just to clarify a bit further.. I am not getting a spark into the distributor cap and i am not hearing the fuel pump kick in..

nick_n_ii

I still think Crank Position sensor

genedog

OK.. could it be that the plug that connects the CPS be bad on the truck side and not the sensor side.. I just purchased the sensor yesterday and put it in.. How can i test to make sure the plug is getting voltage and how much voltage is it supposed to get?

should i hack the plugs and connect it direct by sodering the wires?

ET JEEP

Check your relay socket for power. Pull out the ASD and fuel pump relay. Check for power on the socket that is for pin 30 on the relay. You should have power with key on or off. The socket for pin 86 should have power with the key on.

The PCM control these relays. The ASD tells the fuel pump to turn on. The ASD also feeds the coil. So if it is working right you should have power to the feed side of the coil.

See if this helps.

genedog

Ok.. this sounds good.. i will try it but i have to wait till Wed..

Stan6406

Try the ASD Fuse in the powerbox under the hood

RenoXJ

Ignition switch ?

ET JEEP

The test on pin 86 will determine if it is the ignition switch. When the key is turned to on, pin 86 gets energized thus turning on the relays. With the ASD and fuel pump relays engergized, you should have power to the fuel pump, coil, injectors, if the PCM senses all ok. The ignition switch is working, so far, for the starter.

The no fuel pump running is a problem. When you turn the key on it should run for a few seconds. You should be able to hear it.

genedog

Ok here is what i found out...
ASD & Fuel pump relay ports show 12.8v on pin 30 and 86 (when switched on)
Starter relay port shows 12.8v on pin 30 and 12.8v on 86 when trying to turn on

?? how do i check for the CPS voltage?? Here is what i did..
http://z.about.com/d/autorepair/1/0/d/K/41956751.gif

ignition switched to on
-1.629 on B & C (red on B and black on C) (ohmmeter set to 2k)
-1.358 on A & B (red on B and black on A)

Does this help?