It took 3 yrs,..PMD

[phantom309]

It was idling at the kids school,.it shut off,.
pulled out onto the road accelerated,..it had a fishbite,...
I looked at the wife and we both said "uh-oh"
I said it won't last mu,......it stalled at 30 mph,.

So coasted aways into a parking lot,. opened the hood and unplugged the remote pmd thats mounted in the front bumper nostril,.
un coiled my spare pmd wire that is attached to the spare pmd thats been lying on the inner fender by the brake booster for the past 3 yrs,.
plugged it in,. shut the hood,. and carried on with minimal delay,.

So much for the big fat black new and improved pmd,.
it's running the grey one now,.and i,m on the hunt for another 'spare'

[Robyn]

The nature of the beast.

Nobody has ever made a PMD that does not fail.

These things are to be considered a CONSUMABLE, not all that unlike oil, filters etc.

Sad that the Mfr did not make a better design.

Spares, never leave home without one

Missy

[Robyn]

I have given thought to a scheme to rewire the power feed to the PMD to reroute the 12v source through a relay with a filter inline to suppress any voltage spike.

The power feed to the PMD comes through a convoluted pathway from the ignition switch to the unit itself, with several branch circuits.

The wire that feeds the PMD is very small and could easily be subject to amperage and voltage spikes.

Using a relay connected directly to the battery + and then filtered to maintain a steady power flow might stop the failures.

[MajMike]

I'm sorry, what is the PMD and how often do they go bad (as in do I need a spare too)?

[DmaxMaverick]

I'm sorry, what is the PMD and how often do they go bad (as in do I need a spare too)?

PMD = Pump Mounted Driver

You don't have or need one on your 1982. Only the DS-4 pumps need one, 1994 and later EFI models.

[phantom309]

I'm sorry, what is the PMD and how often do they go bad (as in do I need a spare too)?

http://lmgtfy.com/?q=6.5+diesel+PMD

[DmaxMaverick]

That's rough....

[Robyn]

The PMD has got to be one of the worst inventions known to the world of diesel pickups/SUV

This little black magic box is a nightmare of the worst kind.

The DS4 electronic injection pump was introduced in the 1994 model year of the 6.5 GM diesel and is a totally "DRIVE BY WIRE" injection system.

Your foot has Zero mechanical connection to the injector pump.

The PMD "PUMP MOUNTED DRIVER" OR AKA FUEL SOLENOID DRIVER is a little cigarette pack sized black box that contains 2 large power transistors and a circuit board that control the function of the injector pump.

The onboard ECM (Computer) sends signals to the PMD and it then aplifies these signals to run the injector pump, controlling fuel delivery, timing and such.

When the PMD fails, one of a few things happen.
The engine can just die and thats it.
The engine can die, then restart and die again. (usually when hot)
The throttle can go to full with no control, racing until the ECM shuts it off due to over speed.

The last scenario is the least common, but can get very exciting to say the least :eek:

Missy

[bowtiebutler]

Threads like these sure make a guy glad he's running a good ole DB2. :)

Matt

[phantom309]

I have given thought to a scheme to rewire the power feed to the PMD to reroute the 12v source through a relay with a filter inline to suppress any voltage spike.

The power feed to the PMD comes through a convoluted pathway from the ignition switch to the unit itself, with several branch circuits.

The wire that feeds the PMD is very small and could easily be subject to amperage and voltage spikes.

Using a relay connected directly to the battery + and then filtered to maintain a steady power flow might stop the failures.

I think you are right on track robyn,.

The alternator started overcharging a few days back and i was running with the headlights on for the weekend,.
after i changed the alternator for ANOTHER rebuilt one,.the pmd crapped out,.
so damage done before or after,.??