I'm new to diesels. Apparently my PMD/FSD on my '99 Chevy K3500 started working intermittently shortly after I bought it about a year ago. I never knew when it would die. Sometimes it would start after a short break and other times it was towed.

After the second tow I replaced it with a Dorman and also bought the heat sink and extension cable kit to move the PMD away from the engine and keep it cool. Got them from amazon and they worked great for about six months or so. Then it started doing the same thing. PMD had a lifetime warranty and they replaced it. The replacement died and wouldn't start at the mechanic's shop. I returned it for a refund.

I ordered a new Stanadyne PMD from ebay. It is supposed to be the company that makes the OEM part. It only worked for a day and a half.

Meanwhile, this awesome truck has been parked more than I've driven it.

Has anyone had similar experiences? Thank you for your time!

 

Welcome to Diesel Bombers and the Dorman PMD's are known to be junk right out of the box you have done right by getting a Stanadyne and relocating hopefully behind the front license plate in the bumper next thing make sure the heat sync is grounded and then pull all grounds especially the one one the rear passenger side head and clean them real good and reassemble them, and last but not least any other sensors replace with AC/Delco only.

 

What is the flow rate when you open the drain valve? Should be able to fill up a red solo cup under 30 secs.

Have you straight wired the lift pump? I mounted a switch on the driver's side kick plate for diagnostic purpose. I use the switch to measure the flow, bleed the fuel filter manager in case of running out of diesel, and if it runs fine straight wired it means that the shutoffs might be due to a faulty oil pressure switch.

I had a hard gremlin when I first got my truck, turned out that the diesel sock was clogged and restricting flow. When I pulled out the fuel sender unit the sock fell off in there

I just left it off, but man was my truck reliable after that! Whew, I spent so much money replacing parts.

 

I had that same issue and it was oil presser sensor. It wasn't feeding enough to the injector pump. I replaced then just for good measure checked all connections and cleaned all grounds even though they looked ok. Havnt had a problem since then

 

X2 on the grounds. I had similar grief, and running fresh grounds from the battery to the block, body, frame and HP pump as well as cleaning existing grounds solved many issues like you are having.

 

Have you looked at, or tested the lift pump? I was having a similar issue, hard starts, stalling randomly, low power/acceleration at higher fuel demand speeds. I ran a bypass power source from the ignition power through a switch so i can turn it off, but the pump runs now when i turn the key. (unless I remove the .303 casing from my dash... My little fun idea for a switch)

But what seems to happen is you get a melted contact on your Oil pressure switch, which will still read 12V from the wire heading to the lift pump (in my case anyway) but the fried contact isnt giving the amperage needed to run the pump. The pump in this case is still good to go, you just need to evaluate what you would rather have, a reliable power source or another temporary OPS. All the safety aspect aside. It really doesnt change much since your Injection pump will still keep the truck running regardless. So their idea of a safety feature really isnt valid.

Hopefully that helps!