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Discussion Starter · #21 ·
Next time it dies try pouring a bottle of room temp water on the IP and see if it starts back up.
If it does that is a sign of a tired injection pump
Ok, will do. Are the bubbles from over heated fuel boiling?
 

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Ok, will do. Are the bubbles from over heated fuel boiling?
When pump internal tolerances go out of range the pump no longer works as it should and friction heats things up from a lack of fuel.
When the water is poured onto the pump it cools things just enough to bring the tolerances back into place and the pump starts working
 
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Recently bought a 94 gmc k2500 6.5l turbo diesel for hauling water. Test drive fine and ran great the 45 minute trip home, but after getting home the problems started the next day.

I thought it was the PMD, it was tempted to top of the intake, but still would shut off randomly. I replaced the corroded ground wire and it ran great for one day of hauling then had issues again.
I replaced the PMD but it still shuts off after a few minutes of running and it difficult to restart. Upon restart, great clouds of black smoke and it runs poorly until you spend a few minutes reving it to clear the smoke but then it shuts off again after a few minutes.

The chemo I got for cancer screwed my brain up and it's hard to get it to work well enough for diagnosing the truck.

I think it might be the optical sensor in the injection pump but I can't be sure.

What should I check and how should I check it?
Add fuel pump relay, remove any elec. adds, tdco & then relearn before all of that, to avoid unnecessary $parts purchases$
 

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Discussion Starter · #24 ·
When pump internal tolerances go out of range the pump no longer works as it should and friction heats things up from a lack of fuel.
When the water is poured onto the pump it cools things just enough to bring the tolerances back into place and the pump starts working
Did the water test today, it was an easy restart immediately. Thank you for this advice!
After reading a few articles about ultra low sulfur diesel, I was wondering about your views on a lubricating additive to prolong IP life.
 

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Did the water test today, it was an easy restart immediately. Thank you for this advice!
After reading a few articles about ultra low sulfur diesel, I was wondering about your views on a lubricating additive to prolong IP life.
If you buy a gallon of 2-cycle oil, like the cheap stuff Wal-Mart sells Tc-w3, and add 1 fluid ounce for every 2 gallons of diesel fuel added, it's helpful. Stanadyne and Howe's also make a good lubricity additive. I use a product called kd100d and it's really hard to find it now, but that stuff takes the water out of diesel fuel. Been using it for 12 years, and have not replaced an injection pump or a lift pump in those 12 years. Never gelled in the cold, either.
 

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Did the water test today, it was an easy restart immediately. Thank you for this advice!
After reading a few articles about ultra low sulfur diesel, I was wondering about your views on a lubricating additive to prolong IP life.
As mentioned you can start using TC W3 two stroke oil (1 ounce per two gals. of fuel in the tank ) with every fill up or any other additives out there like Howes, Optilube, etc.
The additive is a must have with our old engines
 

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Discussion Starter · #27 ·
If you buy a gallon of 2-cycle oil, like the cheap stuff Wal-Mart sells Tc-w3, and add 1 fluid ounce for every 2 gallons of diesel fuel added, it's helpful. Stanadyne and Howe's also make a good lubricity additive. I use a product called kd100d and it's really hard to find it now, but that stuff takes the water out of diesel fuel. Been using it for 12 years, and have not replaced an injection pump or a lift pump in those 12 years. Never gelled in the cold, either.
thank you sir, I was hoping this would help prolong the new expensive IP I'm going to have to install.
 

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Discussion Starter · #28 ·
As mentioned you can start using TC W3 two stroke oil (1 ounce per two gals. of fuel in the tank ) with every fill up or any other additives out there like Howes, Optilube, etc.
The additive is a must have with our old engines
Thank you. After reading I kinda figured this was the case.
 

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Welcome to DieselPlace

Go back through all the grounds using this link for reference: Grounds-Grounds-Grounds The importance of good grounds.....
Perform a lift pump test: Reference Material: Lift Pump/OPS
If it fails that test then replace the lift pump and the ops ( Oil pressure switch supplies power to the lift pump and will get weak)

Install a piece of clear fuel line on the return side of the Injection pump to help locate any air in fuel issues, as shown in this link: Question: - 1999 GMC Bluebird 6.5L TD - PMD &amp...
I echo the "grounds advice"...another area to check is whether there is a voltage drop from passenger battery positive to positive bus at firewall. There is an 8 guage cable (and 12 guage fusible link) that runs down with starter cable and then routes up to the bus. I actually had a two volt drop due to a rotted cable. I replaced with 4 guage welding cable and routed behind airbox. Finally, check the harness connections on PMD...an intermittent fault can definitely cause a n intermittent PMD issue. These are all easy to cheer ck. When I replaced the wire to firewall bus...I was amazed at difference...just remember to fuse the new 4 guage line😉
 

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Ok, air bubbles… looks like you need to VERIFY the FFM is leak free. I would just order a new one from Amazon. Also, the fuel line on my truck had a check valve behind the lift pump cut into the line, and the rubber is all cracked and leaks air… you may want to look over the fuel line from lift pump to tank to look for air leaks. Check the lines feeding the FFM, I rerouted ALL my lines above the intake… makes leak checking far simpler…

also, if fuel flows well out the bleeder, and the water drain tap at the front of the motor… that doesn’t prove fuel is flowing THROUGH the filter… also also, when you changed the filter, and cleaned the bowl, did you replace the screen in the center tower? A plugged screen will shut ya down as well.
 

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I just fixed this problem on mine, I pulled the intake and replaced all the original rubber diesel line. Some of them were really badly cracked up at the ends. That seems to have been the somewhat random source of air bubbles that kept showing up. It took all afternoon and you need 3-4 feet of 1/4" and a couple feet of 3/8" diesel rated fuel line, I had some lying around so someone else might have a better estimate. The worst area was actually accessible without pulling the intake, the inlet line for the injection pump was the worst. I probably could have fixed my issue by cutting a tiny bit off both ends of that line and reconnecting it.
 
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