Stalling and Hard Start....

[scot5146]

Hey Y'all

Well it’s been awhile since I have been on the website, which usually means my truck is running good... BUT today I had a few problems...

I was leaving for work, turned on the truck like normal and was surprised at how long it took to start, the truck cranked for a long time about 15 seconds. It then started and ran for a minute letting it warm up, it stalled after about 1 min but kept running...

I was late to work so I pulled it out of the driveway and made it about 50 yards and it shut off completely and the battery light came on...

I then turned off the key and tried it again, fired up and I put it back in the driveway and grab the car to go to work...

So after thinking about it for a few hours, I am leaning towards PMD failure...

Any other idea?

If that is the problem then something is wrong with this truck because I am going through a PMD every 6 months...

Any help would be greatly appreciated!

Thanks:D

Mike

My rig is a 1999 K2500 Suburban, 6.5 Diesel

Firefighter
Vancouver, WA

[DaveBr]

What kind of PMD are you using?

[Robyn]

This sounds like a classic PMD failure.

Do you have the PMD remote mounted ??

The ground wire on the original PMD harness needs to fasten to the injector pump as it was from the factory.

I like the Dtech brand of PMD myself

Some of the troops are using the new one that Stanadyne now offers, but I personally will not buy them.

Stanadyne screwed everyone around for so long, and not until the aftermarket made a better one, did they finally try and fix the problem.

Make sure all your grounds are good. (Batteries cables, engine grounds and such)

Bad grounds can cause a backfeeding situation that will end up damaging the PMD.

Mounting the PMD is a cool spot is the key to long life.
I have had them in the grill, on the inside of the front splash pan (under the radiator) and a few other spots.

The main thing is to have it mounted on a finned heat sink that allows it to stay cool.

Keep us posted

Missy

[greatwhite]

It does sound like a pmd failure.

If you have a scanner pull the codes.

But they are not always revealing with a pmd failure.

A pmd every 6 months means something is not right in your setup.

If you're buying used pmd's, that's probably also part of your problem.

I'm using a Heath diesel pmd setup and it's been running for just over a year now with no issues (well, I did get a touch of corrosion on the pins but that cleaned right up and cruise control problems went away). It's a dtech pmd on thier own mount (at least mine is). Add type says they have a special method of bonding the pmd to the heat sink. Make your own decision on that one....

Main reason I went with Bill's setup is because of his 7 year warranty.

If it fails, at least it's a no cost replacement.

There are other retailers out there that offer the same warranty.

I also carry a spare on a computer heat sink in the glove box. On a 6.5 truck, having a spare pmd is more important than carrying a spare tire...

[scot5146]

Well I have been buying the gray PMD's new,but I am now thinking of trying the Dtech that Roybn suggested...

Also should I replace the harness to the pump?

My rig sat for years, rarely driven before I got it from a buddy...

A bunch of the electrical connectors were pretty lousy, hence why I am leaning toward replacing it and then checking all the grounds...

The PMD is currently remote located with a 6 foot extension harness and the finned cooler to go with it...

Thanks Again

Mike

[greatwhite]

If you have bad connections you should clean them up. Whether it means replacing connectors or cleaning corrosion.

Poor/bad connections cause a myriad of problems like increased circuit resistance which can kill components and change sensor values read by the PCM.

This is also why grounds are important on these trucks. Poor grounds, poor PCM operation...or any other component using a chassis ground as part of that circuit....

[a5150nut]

The cheapest and the first 3 things you want to do are,
1. Clean the grounds and electrical connections
2. Clean the grounds and electrical connections
3. Clean the grounds and electrical connections

And if you don't do anything else, clean the grounds and electrical connections. A spray can of contact cleaner can go a long way. On the battery and heavyer connections, that and a wire or brass brash.:D

[scot5146]

So, first I disconnected and cleaned all the connections that I could get to on the engine, then filled them with Dielectric grease...

The truck seems to run a little better but it will still STUMBLE now and then while at speed (highway), I put in another Used PMD that i had laying around but I know its good...

I got a new injection Pump harness but I am not sure that it will fix the problem, I have not yet installed it.

The PMD is remote mounted near the drivers side battery about 3.5 feet from the original location, is this still not far enough? I have another extension harness that I could move it down near the bumper to stay cooler....


What am I missing???????

Thanks

Mike

[rapidoxidationman]

Any possibility of air being drawn into the fuel system? Does the lift pump work properly?

[greatwhite]

Trouble codes?

[Burning Oil]

Where did you get your extension cable? Are all the wires in it black?
Make sure to get your PMD out of the engine bay, behind bumper is where I recomend.
Having sold only 600-800 of these PMDs I can tell you both Stanadyne and Flight Systems (FS) are great units now. FS had a batch a couple years ago that caused some problems, but fixed the problem. Now I would say they are equal in quality. I've had only 1 Stanadyne warranty return and maybe 7 of the FS, but 0 returns on the FS in last 2 years.
With my cable you don't need to change the short IP harness as it plugs onto both styles of connectors.
I offer 7 year warranty

Edit: FS makes the Dtech PMD, Dtech just relables/repackages it as there own.

[scot5146]

:DWell thats good to know, I am not getting any trouble codes and when its running the truck is running great, good milage and power... It just keeps having an intermittent stumble of the PMD or something...

Yesterday I moved the PMD down to the bumper, But I am thnking that the cable that I got off EBAY may be the problem.

I will order a new cable today and try that!

Thanks Y'all

I will keep you updated!

Mike

[scot5146]

Any possibility of air being drawn into the fuel system? Does the lift pump work properly?

Yes its new and working proper!