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Smoking pmd

Jr5150

Jr5150

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Howdy,
I'm a newbie to this site. I have a 1996 GMC Serria 6.5 with 177k miles. While driving along the truck ran away. I quickly turned the key it stopped. I managed to coast to a driveway. Had it towed back home. At home,I noticed when the key is turned on to wts smoke started comming out of where the pmd is(still on the side of the IP) and I could hear a sizzle as if something was burning. I unplugged the pmd connector turned key no smoke or sizzle. Ordered new pmd from ATRACYPART(not sure what manufacturer)plugged in, no smoke but engine will not start, not even trying too. Purged valve at the fuel filter good fuel there. Did the same with the t handle on the IP, seemed to have good fuel. Checked shut off solenoid looks good, I removed it and it's pulling in with key on. Loosened injector line no fuel dripping out when cranking. Removed 4 glow plugs driver side did the cranking sequence and no fuel. Could I have a air locked IP? Assuming the new pmd is good I plan on removing the 8 GPs and try to get fuel drip at the injector. Any advice would be great.
Thanks
 
I would question that PMD. If You are close to a parts store, it might be possible one of them might have a PMD in stock.
If it were Me and mine, I would get on Leroydiesel.com and order the Flight Systems PMD and extension harness to get the PMD relocated to behind the front bumper.
I have doubts that You are having fuel issues, at least until another PMD is tried.
 
Did you replace the resistor that slides into the PMD when you swapped it? I'm Not sure if that will cause a "no start" but I was just thinking through the steps.
 
Welcome.
Definitely sounds like pmd failure. While typing, the Mramarty posts above me appeared. He is on point.

Inspect the harness really well for damage. Check fuseable link, fuses, etc. Actual smoke Means more than just the pmd failure.
 
I was able to get a Dorman PMD through Oriellys parts store, it is a guaranteed for life unit and so I pack that one for a spare.
I have been running on the grey box Stanadyne unit for several years now with no problems, it may fail tomorrow, We just never know so a spare PMD is a must have to pack along.
Some people also order an extra heat sink and mount the spare heat sink to the vehicle and then mount the spare PMD to the heat sink, they also get a spare PMD plug to keep dirt and crap from getting into the spare PMD, that way, if their PMD fails they can just unplug the failed unit and plug into the good spare. probably wise to get a spare number 5 resistor and install it into the spare PMD. Just be sure that if and when the harness is switched to the spare that the resistor from the failed PMD does not follow the harness over to the spare PMD.
 
Mr marty,
If the new pmd worked, I have the heat sink and extension harness included. Right now I just have it plugged into the factory plug. Has anyone seen one cook like that?
 
Video of a PMD smoking would make some of our days... due to a dislike of the poorly designed PMD system.

Regardless you simply have a massive short that caused the PMD to get hot enough to smoke. Combined with a run-away I would be checking the resistance of the IP components it controls. Start with checking the wiring for any rubbed through shorts in the IP area. You may have even burned up a wire, fusible link, or connector. Something may have shorted out and still be shorted out. May have blown replacement PMD(s) instantly. Or just a shorted PMD and fuse, wire, etc. burned out.

It never hurts to clean the grounds. I would check the batteries and load test them disconnected from each other. When you blow a battery or loose a battery ground: things get Weird QUICK.

You want to go through the Attached as DS4 cal resisters for a hardcore PMD voltages and troubleshooting guide... PDF from here:

DTC's, Cal resistor range, DS 6.5, DB2, 5.7L, info online from Stanadyne!

Looking for the EID assembly elastomer insert drive info and what year it affected of the DB2 pumps to clarify a post of mine for "Ratman" I came across this goldmine. CMY: The Google search I used. :agreed: 1st result: Oldsmobile 1985 doc referencing EID governor here...
www.thetruckstop.us

Jr5150 said:
Mr marty,
If the new pmd worked, I have the heat sink and extension harness included. Right now I just have it plugged into the factory plug. Has anyone seen one cook like that?
Click to expand...

Consider this PMD cooked! X2 Never run one without a heatsink! Heat damage to electronics can show up later when you have forgotten about this... Or "POP!" immediate failure.
 
If your planning out for the future once everything is running again, consider mounting 2 pmd on heatsinks next to each other. Use an old harness end and fill with silicone to use as plug to keep clean and dry until the day it’s needed. If you rather buy one, Bluehummer sells them for a few bucks.
Whenever there is a problem there is no testing a pmd- only “replace with known good”. So being able to just move a wire and know whats up in seconds is super nice. Comes in really handy if it dies or won’t start in dangerous traffic or bad weather situation. A spare pmd is like a spare tire- flat required for that ip.
 
I originally mounted 2 PMD on 2 heatsink in the bumper but after realizing the chance of PMD going out is probably once every 3-4 years, I took the spare and put it inside my toolbox that stays in the truck.
Actually, the last one I got from Leroy has been running for more than 5 years.

Besides, I started to see rust on the screws holding the PMD to heatsink.
So, it is more of not exposing it to the nature and start deteriorating before it can be useful.

Your case may be different at this point.
 
Will L. said:
Welcome.
Definitely sounds like pmd failure. While typing, the Mramarty posts above me appeared. He is on point.

Inspect the harness really well for damage. Check fuseable link, fuses, etc. Actual smoke Means more than just the pmd failure.
Click to expand...
WarWagon said:
Video of a PMD smoking would make some of our days... due to a dislike of the poorly designed PMD system.

Regardless you simply have a massive short that caused the PMD to get hot enough to smoke. Combined with a run-away I would be checking the resistance of the IP components it controls. Start with checking the wiring for any rubbed through shorts in the IP area. You may have even burned up a wire, fusible link, or connector. Something may have shorted out and still be shorted out. May have blown replacement PMD(s) instantly. Or just a shorted PMD and fuse, wire, etc. burned out.

It never hurts to clean the grounds. I would check the batteries and load test them disconnected from each other. When you blow a battery or loose a battery ground: things get Weird QUICK.

You want to go through the Attached as DS4 cal resisters for a hardcore PMD voltages and troubleshooting guide... PDF from here:

DTC's, Cal resistor range, DS 6.5, DB2, 5.7L, info online from Stanadyne!

Looking for the EID assembly elastomer insert drive info and what year it affected of the DB2 pumps to clarify a post of mine for "Ratman" I came across this goldmine. CMY: The Google search I used. :agreed: 1st result: Oldsmobile 1985 doc referencing EID governor here...
www.thetruckstop.us



Consider this PMD cooked! X2 Never run one without a heatsink! Heat damage to electronics can show up later when you have forgotten about this... Or "POP!" immediate failure.
Click to expand...
WarWagon said:
Video of a PMD smoking would make some of our days... due to a dislike of the poorly designed PMD system.

Regardless you simply have a massive short that caused the PMD to get hot enough to smoke. Combined with a run-away I would be checking the resistance of the IP components it controls. Start with checking the wiring for any rubbed through shorts in the IP area. You may have even burned up a wire, fusible link, or connector. Something may have shorted out and still be shorted out. May have blown replacement PMD(s) instantly. Or just a shorted PMD and fuse, wire, etc. burned out.

It never hurts to clean the grounds. I would check the batteries and load test them disconnected from each other. When you blow a battery or loose a battery ground: things get Weird QUICK.

You want to go through the Attached as DS4 cal resisters for a hardcore PMD voltages and troubleshooting guide... PDF from here:

DTC's, Cal resistor range, DS 6.5, DB2, 5.7L, info online from Stanadyne!

Looking for the EID assembly elastomer insert drive info and what year it affected of the DB2 pumps to clarify a post of mine for "Ratman" I came across this goldmine. CMY: The Google search I used. :agreed: 1st result: Oldsmobile 1985 doc referencing EID governor here...
www.thetruckstop.us



Consider this PMD cooked! X2 Never run one without a heatsink! Heat damage to electronics can show up later when you have forgotten about this... Or "POP!" immediate failure.
Click to expand...
 
Twisted Steel Performance said:
If your going to spend money attempting to "fix" the whole PMD thing, spend the time and that money converting the IP to a DB2, problem solved forever... their will never be a PMD that won't fail sooner or later...
Click to expand...
For now, I'm just trying to get it to fire
Twisted Steel Performance said:
If your going to spend money attempting to "fix" the whole PMD thing, spend the time and that money converting the IP to a DB2, problem solved forever... their will never be a PMD that won't fail sooner or later...
Click to expand...
This is the first issue with this truck. I've owned it for 14 years. It's been solid. That's sort of the issue..never had to work on it so troubleshooting has been a challange. I'm just trying to get it to fire right now. I tried my second new pmd(cardone) and still the same result, no fuel at the injectors. I'm thinking the pump is airlocked or the ecm.
 
Jr5150 said:
I'm thinking the pump is airlocked or the ecm.
Click to expand...

Bluntly: QUIT GUESSING!!!
You have ZERO idea it's the ECM or air in the system. Guessing will only frustrate you and waste money with questionable parts thrown at it.

Now ECM: what are the dash lights doing on Key On? Do you have a STS and SES light? Yes: ECM has power.

Air in system? Put a clear return line on the IP and look for air.

With the above two you could have any number of electrical problems: fuses popped, fusible links blown, wires burned out, connectors burned out, shorted items in the IP. Pull and inspect Every. Single. Fuse.

You separated the batteries and load tested them? One blown bad battery and cranking draw can brown out (fail to work while cranking) the ECM.

I would start with the fuel shut off solenoid and make sure it's getting 12v to open. Then probe the voltages in the PMD as the PDF I linked to above. If trons are out of your ability, know your limitations, and find an automotive electrical repair shop: it will be cheaper than throwing parts at it and HOPE.
 
Last edited:
WarWagon said:
Bluntly: QUIT GUESSING!!!
You have ZERO idea it's the ECM or air in the system. Guessing will only frustrate you and waste money with questionable parts thrown at it.

Now ECM: what are the dash lights doing on Key On? Do you have a STS and SES light? Yes: ECM has power.

Air in system? Put a clear return line on the IP and look for air.

With the above two you could have any number of electrical problems: fuses popped, fusible links blown, wires burned out, connectors burned out, shorted items in the IP. Pull and inspect Every. Single. Fuse.

You separated the batteries and load tested them? One blown bad battery and cranking draw can brown out (fail to work while cranking) the ECM.

I would start with the fuel shut off solenoid and make sure it's getting 12v to open. Then probe the voltages in the PMD as the PDF I linked to above. If trons are out of your ability, know your limitations, and find an automotive electrical repair shop: it will be cheaper than throwing parts at it and HOPE.
Click to expand...
W wagon,
I appreciate your passion and concern but simply replacing a pmd that is smoking like crazy is Not throwing money or guessing. I've checked everything you've suggested. I'm getting good fuel to the pump but zero to the injectors.
I keep a charger on batteries when cranking for that purpose. I am getting STS and SES. Does that mean the ECM is communicating with the pmd and IP?
 
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