It wasn't the PCM: What else could it be?

[Stellaplease]

I originally took my jeep in when I thought I was having a misfiring issue. In any gear the jeep starts to stall like it's not getting fuel. Take my foot of the gas and press back down it works. When this happens all the gauges lose power and the check engine light temporarily comes on. But as I said take my foot of the gas it all stops and all gauges go back up and check engine light goes off. Theres no specific RPM that this occurs at. I have taken it into 2 different shops for digognostic and they can not see any issue. I tried to drive when having a computer plugged in and when the issue occures the digognostic machine says it is reestablishing a connection. Reading some other post and forms I was sure it was the ECU. I purchased and replaced it and the issue is still occurring. Any ideas???

 

[AndyG]

Yes, the connection that is being re-established is likely a bad ground .

Check every ground , and remember they can break down inside the cable housing and appear fine.

 

[Goatman]

A bad ground can display so many different ways. Bad primary power can do it too. Almost all electric problems make me check the ground wires first. I try to start with the cheap and easy solutions first.

 

[Stellaplease]

Yes, the connection that is being re-established is likely a bad ground .

Check every ground , and remember they can break down inside the cable housing and appear fine.

Ok, I was looking last night with no luck. Is there anywhere to find a diagram of factory grounding locations? I have found what I think is a list of them but I'm new to this and pictures would be so much more help.

 

[AndyG]

Yes I think if you'll go to frequently asked questions on here or just post a thread stating that you need that particular diagram I feel confident you will find it.

you can use the search engine on the forum also and there may be one on here already.

Good luck, keep us posted ..when you do, we all learn.

 

[Stellaplease]

Yes, the connection that is being re-established is likely a bad ground .

Check every ground , and remember they can break down inside the cable housing and appear fine.

Quick follow up question to this now that I am checking grounds. You said the housing could be bad/wires inside. Should I be using a multimeter to check since I'm already checking each ground? I should be getting close to zero right?

 

[Chris]

This is an obvious question, but is it throwing any codes (pending or stored)?

 

[AndyG]

Quick follow up question to this now that I am checking grounds. You said the housing could be bad/wires inside. Should I be using a multimeter to check since I'm already checking each ground? I should be getting close to zero right?

since you're dealing with multi-strand wire I'm not sure you'll get a consistent reading.... You can be touching wires that are good... And have broken wires on the path

 

[Stellaplease]

This is an obvious question, but is it throwing any codes (pending or stored)?

No codes at all, not at 2 different shops I took it to. I have a buddy who suggested to drive with the OBD(E) reader? (I forget exactly what it is called) plugged in while driving. Every time the issue occurs the reader would lose connection and have to reestablish.

 

[Chris]

No codes at all, not at 2 different shops I took it to. I have a buddy who suggested to drive with the OBD(E) reader? (I forget exactly what it is called) plugged in while driving. Every time the issue occurs the reader would lose connection and have to reestablish.

Yes, if you could data log with it while driving using a wideband O2 sensor and software, or an OBDII reader with data logging capabilities, that could be pretty telling.

 

[T Crawford]

Can you share a photo of your engine bay, battery and the firewall around the valve cover. Check your ground cable off the negative battery terminal and positive wire going to starter and power distribution block, could have internal corrosion