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-   -   No Start, Need Suggestions (http://www.jeepforum.com/forum/f13/no-start-need-suggestions-1609601/)

robertflake 09-21-2013 05:18 PM

No Start, Need Suggestions
 
1998 ZJ 5.2 Limited.

Was driving 70mph and the truck died. Started again on the side of the road and died a few minutes later, would not start again.

Will not start, No spark. Poured a little gas in the throttle body and turned the key: nothing.

I have searched and searched for things wrong with this problem and have checked them all and they are all good. I am leaning towards a bad computer, but I am not one to buy a part without KNOWING that it is causing the problem. My question is this:

Is there a definitive way to tell that the computer is bad using an ohm meter?

Things I have checked: ASD relay (good), ohmed out the crank and camshaft position sensors (both are good), put a spark light on the ignition module (got a light), checked the O2 sensor wiring(No faults), good voltage on the battery (13vdc).

Did a general tune up about 10 months ago when I had another no start problem, it ended up being a bad camshaft sensor but in the process I changed plugs, wires, cap, distributor rotor, ignition module and crankshaft pos sensor.

I don't think there is any correlation but this happened the day after I fixed a cracked door latch mechanism, after the repair the dome lights will not turn off after the door is closed now (light switch ohms good), no fuses blown.

It has been two weeks and I can't figure it out. I want the broke thing out of my driveway! lol

Please Help!

ZeeJay1997 09-21-2013 05:22 PM

Quote:

Originally Posted by robertflake (Post 16203505)
Is there a definitive way to tell that the computer is bad using an ohm meter?

No. Mr Mopar has kept all of that a closely guarded secret.

Does the CEL come on for 3 seconds when the switch is placed to the ON position?

robertflake 09-21-2013 05:31 PM

Quote:

Originally Posted by ZeeJay1997 (Post 16203577)
Does the CEL come on for 3 seconds when the switch is placed to the ON position?

Forgot to mention that, yes it does come on for three seconds after the key is turned on, then goes off...

There is not a CEL code thrown.

ZeeJay1997 09-21-2013 05:41 PM

Do you have 5v at the two outside contacts on the disconnected TPS connector with the switch in the on position?

robertflake 09-21-2013 05:51 PM

Quote:

Originally Posted by ZeeJay1997 (Post 16204073)
Do you have 5v at the two outside contacts on the disconnected TPS connector with the switch in the on position?

No. I am getting between 1.6 and 2.6 VDC with the ignition ON and the TPS plug OFF the TPS.

The TPS is the one that is on the throttle body, not the one forward of the throttle body correct?

ZeeJay1997 09-21-2013 05:57 PM

yes, its in line with the throttle plate shaft. unplug the crank sensor and read the voltage on the tps connector

robertflake 09-21-2013 06:03 PM

Damn! Its too late today to try it, I will try in the AM... besides, it is a PITA to disconnect that crank sensor...

Just curious, why am I disconnecting the crank sensor and checking the disconnected TPS?

ZeeJay1997 09-21-2013 06:11 PM

I'm checking to be sure you checked the crank sensor correctly. Sometimes, the crank sensor will fail and load the 5v circuit in the PCM. It may or may not completely disable the PCM.

When there no CEL, the PCM is disabled, so the fact that you have the CEL at key on is a positive sign that the PCM is not dead.

These are just some steps to check the output of the PCM.

Read through the link below for more ideas, i have a b allgame to watch.

robertflake 09-22-2013 11:11 AM

Disconnected the crank sensor and read 5.13 VDC at the two outside pins of the TPS harness, what does that mean?

ZeeJay1997 09-22-2013 01:31 PM

it means you need to find a mopar crank sensor. it is overloading the 5v circuit

robertflake 09-22-2013 01:45 PM

Awesome! I'm glad that I have without a doubt located the problem... Can anyone give me an OEM part number? The one I changed was an aftermarket crap one and need to get the right one... I found a Delphi one at advance auto and need to know if that is the right one.

Rich93ZJ 09-22-2013 07:01 PM

You are now at the mercy of the dealer. Only place to get genuine Mopar parts unless you order online.

ZeeJay1997 09-22-2013 09:20 PM

i've been looking around for a replacement for mine. Mopar overstock carries the sensor but I dont think they are genuine Mopar. Additionally, they make you give your information before they give you shipping costs, so I opt out.

The last one i bought 3 years from NAPA was a Sorenson and i havent had any trouble with it.

Dealer will probably tell you they are on nationwide back order.

You are looking for PN 52067868

AnotherRedZj 09-22-2013 10:02 PM

I usually check factorymoparparts.com or wholesalemopar.com for my parts

ZeeJay1997 09-22-2013 10:13 PM

Quote:

Originally Posted by AnotherRedZj (Post 16234777)
I usually check factorymoparparts.com or wholesalemopar.com for my parts

Have you (or anyone else) ever ordered anything from them?


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