OT: Jeep wrangler stalling, no gauges

[ratsflif]

Ok so some more research, I downloaded the service manual and did some reading about the PCM.  The PCM has 3 large connectors going to it, I removed  them checked the connections and put them back on.

In the service manual it says that the PCM outputs to the auto shutdown relay, voltmeter, fuel gauge, tach..... basically all the gauges that are dying.

So, anyone have any troubleshooting steps I should try with the PCM?

[Mojo_114]

PLEASE DO 3 THINGS FOR ME.
1. Swap the relays arround. Move each 1 step to the right.
2. The Maxi-Fuses, check and reseat all of them. Take a flashlight and look into the fuse block for a cooked end--inside.
3. While sitting in the driveway(engine running) jiggle the key in the ignition. Does any guages go dead when you do this.
4. Jiggle the wireharness near the fuse block and near the brain(running) and not too hard. Does anything happen.

Question:
Does it stall when it is wet (like going through a puddle).

Idea:
If this is a inline 6, below the distribuiter there is a plug(on pass side). Inspect, this is a somewhat common problem.

[ratsflif]

Checked the fuse block and rotated all the relays.  Jiggling wires near pcm, and fuse box while running does nothing.  Jiggling key in ignition while running does nothing.

Has nothing to do with wetness this started after being in the garage for 2 days, and stalled on a beautiful day after driving about 200 feet.  It seems completely random, sometime when idle at a red light some times when just cruising along not accelerating.  Sometimes it will work all day without any issues.

yes this is the inline 6 engine.  I will have to check the plug on the distributer in the morning.

Thanks for the tips, I see where your going with the ignition switch and the wires on the fuse box.

If the Jeep stalls normally (like from a bad shift out of first) then the battery gauge and fuel gauge stay on working correctly, when this random stall happens all the gauges die.

Im driving back from New Port Richey in a little bit, so we will see what happens.....

[TheBatman]

Rat,

my dad says it's most common problem to be the Electronic Control Module (ECM) that make sure is getting power to it, there's also a fuse for it in the fuse block.  Also, need to check all the grounds as corrosion and bad grounds will cause issues.  Also, check something called a Schreder valve on fuel rail to make sure it's shooting gas from fuel pump, and make sure fuel pump is working. Also the rollover shutoff switch may be bad, which kills the engine when car is rolled over.

[TheBatman]

OK,

now I read him your codes, he says you need to replace both sensors....one on camshaft and other one on crankshaft.  He said that should do it according to those codes you posted. 

[ratsflif]

Thanks for the continued help.

I'll replace the cam sensor it's only like $20.  But with the gauges dying and the computer codes reseting it really looks like something more.  I think the codes that I was getting were from the stall happening, not what caused the stall.  Now that I have the 1666 page service manual I can really narrow down the problem........

When I swapped the relays I made sure i swapped the auto shut off with the horn.  I was reading on how many things effect the pcm from the ignition switch to auto shut off relay to the common ground it shares with all the other electronics in the jeep; sounds like the netbook, multimeter and I have a date with the jeep tomorrow.

Now that I replaced the plugs it is having a much easier time recovering from the stalls, so thats one good thing...

I think the real problem troubleshooting this is how random it happens and once its done with its stalling fit, its back to running perfect.  I drove to New Port Richey and back, about 30 miles without any problems.

I really appreciate the help, never had to work on any of my previous, foreign, cars   

[TheBatman]

Well, those plugs looked like crap anyway, so that's at least something you found that needed to be done regardless.

[ratsflif]

Can anyone point me to the location of the camshaft position sensor?

I found it.....

[ratsflif]

Yes, I replaced all 6 plugs and it runs much smoother.

So here is todays tale, no stalls.......but

It almost stalled twice, I drove about 70 miles today and lost the gauges on the instrument panel twice.  The jeep kicked a few times like it was going to stall, the tach fluctuated and then the gauges went dead, but the engine stayed running.  This happened both times, once I was stopped at a red light I turned it off and back on and the gauges went back to normal.

[Todd]

Bad computers throw all kinds of weird codes and cause strange running conditions on vehicles. I just replaced one on a 05 3500 Diesel that had 7 codes in the system, the transmission had a prolonged 1-2 shift and the vehicle had a long crank before start. The transmission was bad and the computer was bad as well. All the codes went away after the computer was replaced and a new crank sensor code showed up. We diagnosed the crank sensor as bad, replaced and the prolonged crank stopped.

The first thing my guys would say after you have replaced the obvious is to get it diagnosed. You have no reason to switch out the computer unless you know for sure it is bad. There is a reason why a shop has thousands of dollars invested into diagnostic equipment and you unfortunately will need to utilize that equipment at this point to know for sure what the best course of action is. It is too hard to tell someone what to do next when it involves complex diagnostic flow charts requesting that you use a $10,000 tool in your hand to get you to the next step.

You may luck into it and a lot of the stuff you have replaced is better off being replaced on the vehicle since it looked terrible but you may be at a point where you want a legitimate ASE Master Tech on your vehicle. I know guys without qualifications recognized by ASE can fix cars too but at least you know that you are dealing with a guy who took the initiative to better himself at his trade through the academics behind every vehicle system. Don't go to a parts changer at this point.

This is all just my opinion of course. If you want to have it checked out at my shop we are unfortunately far away in Bonita Springs. The shop is AAMCO of Bonita Springs. My lead tech is a re certified ASE Master Technician with Ford factory training. I also have another master level technician on staff. I have a builder that is at an industry equivalent master level and another builder that has Ford factory training too. We do a lot of work for other shops and see our fair share of diagnostic hairballs that others throw their hands up at. We could fix it but it would need to be here of course.

Again, just my 2 cents. Good luck getting to the bottom of the problem. Also, car-part.com can be your friend in a tight money situation. You can get pcm's and any other used items you may wish to get. I don't like used parts but sometimes if the wallet won't allow new then it may be the way to go.

Todd

[Todd]

Hey, missed the post where you said that it stopped stalling but still had issues. I wonder if you need to reset the cam and crank sensor timing now? I will ask my tech tomorrow if that is a requirement on that vehicle. Identafix had reports of gauges going crazy with crank issues too so disregard my last post and let me see if you may almost be there.

Darn, I wish I would have paid more attention to all the posts before writing that last book of a post. 

Todd

[Todd]

Yeah, he says that you should not have to reset the cam crank timing on that vehicle.

Todd

[ratsflif]

Thank you, for helping out.  I didint drive much over the weekend but the few times I did I didnt have any problems.  Im going to pull apart the dash and check all the wiring, it has been out in the rain a few times with the top off...

[ratsflif]

It was the PCM.  The jeep started stalling every time I would take it out so I ordered a new PCM/ECU whatever..  Running like a champ now.

Thanks again guys for the help troubleshooting.