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-   -   Time for my thrid pcm? (http://www.jeepforum.com/forum/f13/time-my-thrid-pcm-1612361/)

cgcarpenter 09-22-2013 04:23 PM

Time for my thrid pcm?
 
Well this zj caught the electrical gremlin and it brought friends lol

It's continuously getting worse.
Stalling bucking hesitating misfire backfire. She decides she's a moody ***** lately. Whenever she wants. There's no tell on when it'll happen.


I've got codes:
P0108 map sensor voltage high
P0351 peak primary circuit current not achieved within maximum dwell time.
P0320 no crank at PCM during cranking(starts just fine)
And a cylinder 3 misfire code.

Where do I go from here. These sensors are all fine. Should I bite the bullet and buy a new PCM?

Oldfrog 09-22-2013 07:39 PM

It's not a Cardone is it?
If so, that's the PCM I just turned in, under warranty. They sold it to you...chuckle..:rtft:

Make sure you have NTK o2 sensors installed.
Next time it stalls, pull over, leave the key on and remove the TPS connector, check the voltage on the 2 outside wires. See if you get 5volts. Turn the key off, then put it back on.

I bet it has 5 volts and starts right up, too.

neonhomer 09-22-2013 08:52 PM

Do tell.... My 96 ZJ has a "die at random" issue... If you try to restart it without cycling the key, it won't refire. If you cycle the key off, wait a few seconds, and then try to start it, it will usually fire back up. I get the P0351 code - P0351 Ignition Coil A Primary/Secondary Circuit Malfunction.... I've replaced the coil, and the crank sensor was recently replaced with a Mopar sensor.

cgcarpenter 09-22-2013 09:09 PM

Quote:

Originally Posted by Oldfrog
It's not a Cardone is it? If so, that's the PCM I just turned in, under warranty. They sold it to you...chuckle..:rtft: Make sure you have NTK o2 sensors installed. Next time it stalls, pull over, leave the key on and remove the TPS connector, check the voltage on the 2 outside wires. See if you get 5volts. Turn the key off, then put it back on. I bet it has 5 volts and starts right up, too.

Yeah I think it's a cardone one. But it's a year and a half old. I have smog soon so I'm ordering some from rock auto.

What would that test reveal?

cgcarpenter 09-22-2013 09:09 PM

Quote:

Originally Posted by neonhomer
Do tell.... My 96 ZJ has a "die at random" issue... If you try to restart it without cycling the key, it won't refire. If you cycle the key off, wait a few seconds, and then try to start it, it will usually fire back up. I get the P0351 code - P0351 Ignition Coil A Primary/Secondary Circuit Malfunction.... I've replaced the coil, and the crank sensor was recently replaced with a Mopar sensor.

Sounds like a fuel pressure problem

cgcarpenter 09-23-2013 12:52 AM

Disconnected my upstream O2 sensor and boom huge difference. Ran 95% better. Except for the cylinder 3 misfire.

Didn't get get a single hiccup all the way home from work or when I ran to the gas station.

Am I speaking too soon?

Probably but I'll see tomorrow morning when I drive to class.

Fingers crossed.

cgcarpenter 09-23-2013 04:45 PM

Ran great all morning.

Except for one complete shutoff in a McDonald's drive through. Lol

Ordering my O2 sensors and then I'll go from there.

cgcarpenter 09-24-2013 01:17 AM

Ran good all the way to work and all the way home.

Ordering new O2 sensors right now.

Felonious_monk 09-24-2013 06:11 AM

I can't help with your question, but I have a brand new computer for sale. I'd let it go for $150.

Oldfrog 09-24-2013 11:36 AM

Quote:

Originally Posted by cgcarpenter (Post 16233369)
Yeah I think it's a cardone one. But it's a year and a half old. I have smog soon so I'm ordering some from rock auto.

What would that test reveal?

Whether or not the 5 volt supply is getting shut down or pulled to ground by another sensor in that circuit....such as a crank sensor.

If you are getting ...say....2 volts..( key on, but not started) ..then you would disconnect the crank sensor, then re-check the tps sensor plug ( wiring harness side) and if it went back to 5 volts, you would know that the crank sensor was pulling it to ground. In that case....you would replace the crank sensor.

But if the tps had 5 volts to begin with, then something else is causing the PCM to activate the ASD relay and shutting the engine down....such as a bad 12volt feed to the PCM or, as in my recent case, the pcm itself.


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