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Is it the PMD or the ECM/PCM?

The cables corrode inside where you cant see it and especially the grounds.
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Excellent point! Automotive cables are flexable (for good reason) - A cable that's corroded under the insulation will feel *crunchy* when you flex it. Usually near a terminal point.
 
Before you go PCM route (those rarely fail) I'll 3rd the recommendation on internal wire corrosion over time, corrosion/moisture "wicks" it's way into a wire, had a buddy with similar issues, insulation break down at firewall pass thru fitting was where he found his problem, also rare but a possibility
 
Next time it stalls, run out and crack the bleeder on the fuel filter and see if it hisses (air/lack of fuel). Then with it up,jump the LP underhood and make sure pure fuel comes out. Pay extra attention to PCM fuse underhood box.


Clean your PMD connections again.
 
Should not be a lift issue, could be air but would have to be gross air intrusion to shut it down and leep it shut down, on OBD-II you can force lift to run, key on and apply 12V to test jumper, open filter mgr drain and look for air bubbles.
 
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Hi all thanks for all the posts.
I know it is not a lift pump. I have tested this on the three 6.5l trucks i have access to and all of them started with the lift pump completely disconnected(They actually ran pretty well too which shocked me). This is definately some kind of electrical problem, like a corroded or broken wire.
I have given up and brought it to the shop. They had the truck all this last week. they but 25 miles on it each day. It took 3 days for it to finally stall on them. They told me that they narrowed it down to the fuel shutoff solenoid. They said they could tap on it and the truck would stall. So they put that in on thursday, today(friday). THe shop manager took it for one last drive to make sure everything was good, the truck proceeded to STALL TWICE! on him. Finally it is someone elses problem.
This one really is a stumper.
 
Have you read for codes? Have you had a bad batch of diesel? A bad batch of diesel will screw with the optical sensor and give it these symptoms, but you get codes along with it(ses light). Does it start hard, take a few seconds to light off? i had the exact same symptoms with my truck, also had codes. i replaced to optical sensor and it fired right up, no more codes, but still stalled. Then i replaced the FSD and no more problems.
 
You should tell him to come to the site to help fix asap. Could end up saving you a ton of time/money in labor/parts and help him fix it faster.
 
There have never been any codes. I wish it had codes then there would be something to go after.
The truck shuts off / stalls just like you turn the key off. It will then not fire, like it has no fuel, it turns over plenty fast. You will also not have glowplug/WTS light. If you continue to cycle the key(off/start/off/start) eventually you will see the WTS light flick on. When this happens the truck will start immeadiately and run perfect. The time that it takes for the WTS light to finally cycle is random, sometimes 30 secs, sometime 10 mins.
The truck has a new heath pmd kit on it, new lift pump, brand new ignition switch, brand new fuel shutoff solenoid, new batteries. Grounds have all been cleaned and checked.
I had some bad diesel in it before , then it runs wierd, currently when it is not stalled it runs perfect.
Shop has also test fuel pressure and such while running and all is good.
 
Have you tried running a separate ground wire directly from the fire wall to battery - post?
 
Does the SES light work, when you trun key to ON? You said STS doesnt.

To me it sounds like bad power to the PCM. Should check the harnesses for the power it is supposed to be getting from the ignition, maybe that line is messed up or shorting. could do continuity or insulation resistance test on it. Also check each ground in the harness that it is making its ground connection.

IF they wiggled the FSD and actually caused an issue puts something back on the PMD since it sends signals, and the PCM. Id do continuity and insulation resitance checks on the PMD extension cable. I havent thought of how it would inhibit the dash lights though.
 
Have the same problem, replaced the ign. switch (AC Delco) and installed a new FSD at the bumper.
Ohm-ed the important wires (power and grounds) to the PCM.
Finally pulled the PCM and re flowed every connection on the circuit board for the connectors.
Still testing.
Lets know how it works out.
 
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