After a 2 hour drive going to Elk camp I stoped and fueled up, and when I came out after paying the truck would not start. It cranked over fast, but no go. After half an hour I drew some fuel out of the T valve and dumped it in the intake where the air filter indicator is and it started up , ran rough for a minute then died. I did this again and it stayed running, and seemed to have cleared the problem. {There were no codes showing} During the week I started it several times, and it seemed fine. The drive home was 3 and a half hours on the highway and it seemed to run pretty good for the first 2 hours then the power seemed to drop off on the hills. Half an hour from home it shut off momentarily for a couple seconds twice in about 30 seconds, then it seemed to be ok .
I made it home , unpacked and decided to do the lift pump test, and started it up after it sat for about 4 hours. Started fine, ran 30 seconds and died. Now it will not fire up at all. I tried last night to re start several times and not a chance. it turns over fast, but no fire in the hole. same thing this morning.
I took the hose from the T valve and drew a quart of fuel with the lift pump on and it gave a good full hose of flow.

The glow plugs seem to be working, I can't find any fuses blown, and I have tried a known working PMD.
The crank Position sensor was replaced 3 or 4 thousand KM ago .

So now I am at a total loss on what to trouble shoot or how to do it. There are no codes showing or stored in the computer.

 

Where did this "known working PMD" come from? Was it off another truck? Did you try "your" PMD on the other truck to see if it works? That sounds like classic PMD symtoms of it starting to fail or finally failing.

 

The PMD is the backup I have installed on the Heatsink on the truck. I ran it before it became a spare backup so I know it works..

 

OK got it. Its been so long since Ive owned one of these trucks. The 6.5 TD I had, had pretty much the same symtoms. It turned out to be that pesky PMD. Bought a new one and relocated it, and didnt have any more issues for the next 5 yrs I owned it, before selling it. Sorry I wasnt much help bro.

 

Thanks for trying Redd. I have been reading a lot of threads on this issue, and a few things come up that might be easy to try . 1 is a different extension harness for the PMD, and I have one , another is the optical sensor disconnect. Apparently it should run if the crank sensor is good, and I just replaced the crank sensor, so it is to cheap/free try to unplug the optical sensor and see if that works..

 

I know those issues can be rather frustrating. Good Luck and hope ya get running soon bro. cheers

 

now I am back to a running engine that is purring like a kitten in a dairy.

I had a second PMD harness, so I wanted to try it, but the old one was connected under the manifold beside the original PMD and hard to get at. I took off the EGR/intake plenum to access the PMD plug and while I was there I unplugged the optical sensor.
Popped the top back on and turned the key, it started hard and ran rough but it ran. Next off came the top again and I plugged the Optical sensor back in and she is purring like a kitten in a dairy , it starts on the first compression stroke it seems like too.
Whether the harness was faulty, or the connection to the factory PMD harness or optical sensor was corroded/bad contact etc. I don't really know but I am back running just fine now.
And all it cost was a bunch of soap to wash my hands with.

 

Very Nice!!! Good Job! Just for the future ya might wanna get some di-electric grease, and clean all connections, then apply some of the grease to the connections. this will keep the connections from corroding and also keeps moisture out. Also, every once in a while, clean all your ground connections as well, from battery to frame to body panel(s), and where ever else there's a ground contact.

 

I had forgotten about this thread and just returned to it. I am having the same symptoms again. This time I have been tearing out my hair. PMD check by using 3 known good PMD's still no fire in the hole.
Disconected Optical sensor, no fire, disconnected Fuel solenoid, took it out and jumper wired it. It opens and closes. Tested the wire conector and it is getting voltage with the key on so I Put it back in the pump and no fire. The pump was full when I removed the solenoid so I know it is getting fuel. Also tested lift pump and lots of fuel coming out the T drain.
Now I can relax, have a steak and go back to what the original fix was last fall, a PMD wire harness check.
I hope this is the problem, and a good cleaning of the contacts is all It needs along with the Dielectrc grease Big Red advised me to use last fall.

 

After a lot of testing in places I have no Idea what they are, I am running again. It seems the problem goes back to what happened last fall . Same thing all over. I ended up finding this thread form the fall and got on track again. It seems the contacts in the PMD harness , or the optical sensor plug were at fault again. I removed the extension harness and got good Ohm reading on each wire , cleaned both ends with contact cleaner and it started up and ran. Died a minute later, and after unplugging the PMD harness and optical sensor plug ,cleaning again and reinstalling it is running good, and starting up , all codes are gone too.
I need to get some Dielectric , grease and load up the plugs, and then tape everything up tight like I should have done in November.
Glad I didn't buy any parts.
There is a poster above than can smile to himself, think "I told him to grease those connections".