PMD issues again???

[mhotao]

Have owned 6.5 since new 1996. 244000 on clock have had 4 PMD over this time. Last April put a NEW one lasted 3000 miles or so Warrantyv by my repair shop. Newest lasted only 1000 miles. Repair shop says it can,t be PMD again because they have been improved. Is ther any thing inline with PMD that could be causing same breakdown symptoms as a bad PMD. Thanks for any input.

[rapidoxidationman]

Do you still have it mounted on the injector pump or have you tried an extention cable and a heat sink on the fender wall? How does the plug look?

[racer55]

Where is the PMD mounted now?
What is it mounted to?
Has heat transfer paste/pad been used between the PMD and heatsink?
Can you post a picture of it?

[scot5146]

I finally moved mine down in the bumper and the issue stopped...

my 2 cents

mike

[mhotao]

This last one has been moved to outside of intake area. Not on a heatsink. At my request this was done my repair shop seemed to feel it wasnt needed to be done {moved}. Thinking of buying a new PMD and when she shuts down change it right away to prove #4 PMD is bad. All of them were replaced with new ones according to the repair shop....

[john8662]

These new Grey Stanadyne PMD's are not as resistant to heat as the black ones they replaced. They have to be mounted to the pump or completly outside of the engine bay to last.

Anything but on the pump or outside of the engine bay on a cooler is a recipe for a bad PMD.

[Robyn]

I agree 100%
Get a fresh PMD (I am not a fan of Stanadyne) Dtech units have srved me well.

Mount the thing on a good finned heat sink and mount down inside the front splash pan.

Make sure to use heat sink paste between the PMD and the cooler.

Heat kills these things, and quickly.

Back in the early days, we went through 4 PMD BOXES in less than a year.

Granted this was before the aftermarket and remote mounting.

Always carry a spare that is ready to go with the resistor installed.

I always carried a spare on a cooler that I could plug in under the hood as a GET ME HOME UNIT


Missy

[BrentN]

I second Robyns backup plan.

I have the good oem PMD still mounted to the IP but unhooked. My main DTECH PMD is mounted to a large finned heat sink next to my brake reservoir and just for good measure, a known good Stanadyne PMD sitting in my console.

Just like in the day when people with Fords kept their Ignition module in their glove boxes or a set of points. We know that this is a "feature" of our vehicles.

Use the Boy Scout motto...Be Prepared.

[arveetek]

This last one has been moved to outside of intake area. Not on a heatsink. .

You're running a PMD without being mounted to the pump or on a heatsink? This will definitely destroy the PMD/FSD very quickly.

The PMD/FSD MUST be mounted to the pump or to a heatsink in order to dissipate heat correctly.

Even with my PMD on a PMD Cooler, I can't even begin to touch the cooler after driving on a hot day, there is that much heat being generated!

Casey

[Robyn]

Definately dont run with the PMD not on a heat sink.

The original concept of the PMD on the IP was theoretically sound, sadly the IP sits down in a hole that can reach very high temps and the pump simply cant soak away all the heat.

The idea was that the cool fuel from the tank circulating through the IP would pull away all the heat, WRONG.

Get that PMD out of the engine bay and into cool air.

The bumper nostril, the area above the splash pan, or any place that there is cool air.

The underhood temps can run 250F or more on a hot day.

The PMD is a delicate electronic device and does not tollerate heat well.

Even with the PMD in cool air on a heat sink, they can still fail.

That is why we carry a spare.

Having one on a heat sink that you can toss in on the intake and plug in quickly can be a real plus if it quits in traffic. :eek:


Good luck

Missy

[mhotao]

You have made up my mind for me. I am gonna buy a new PMD on my own with heatsink assembly extention cable and find a place where I can get air to it. Thanks for all the input. I still love this Suburban but gotta get my wife back to driving it without feeling its gonna shut down on her. Thanks again MHO

[Robyn]

Good luck


Missy