Electric pump only to prime system...

[Craig58]

Typ4, in re reading your post I saw at the bottom you referenced a Detroit primary? I googled that and it showed a filter head...did you replaced the OEM filter head and replace it with one from this company?

 

[Farmer Rock]

So an update to my selected method to try and get my truck running reliably again. Finally got to the point of ordering the fuel pump from Pegasus Racing. So I called them and talked with their technical department explaining what my issue was concerning my truck. To my surprise, they strongly discouraged using their pumps to mask the problem! The person I spoke to said I needed to find the place where the air is getting into the system, repair it and then if I wanted to convert to an electric pump then do it. He said if I have an air intrusion problem the pump will just pump more air creating a bigger problem. So I'm going back to the drawing board on how to fix my truck. Farmer Rock, you suggested fixing my problem by finding the air intrusion point. Would you consider sharing a step by step procedure to go through my fuel system to isolate my problem?

Start with the easy stuff first as with anything. I would look at all the fuel lines first, and do not over look the metal lines before the lift pump. I have had those metal lines rust through on top where you couldn't see, and suck in air but not leak any fuel. Then check the fuel filter head like @gnathv said. There are olive seals in the hard lines that can cause these drainback issues. How does it run after it starts up? Is it only having starting trouble, or is it sucking air while running? This sounds more like a drainback issue from what you previously described, but I am making sure nothing changed. Some times both issues can happen at once (depends on where it's letting air in) so this is the best way of narrowing it down.



Rock

 

[Craig58]

Thanks for responding Rock, it only has issues getting started. When running, it runs perfectly! Can't remember exactly but it's only been in the last year or so that Ive had this issue. I used to be able to throttle it after initial startup and keep it running but now it starts up, surges and dies! And only after cranking and bleeding through the shrader valve can I get it started

 

[Craig58]

Will start isolating this coming weekend per your response. If the olive rubber is bad or hard where can I get new ones from?

 

[Farmer Rock]

Will start isolating this coming weekend per your response. If the olive rubber is bad or hard where can I get new ones from?

https://russrepair.com/olives-and-o-rings-for-a-fuel-system-seal-up/
This actually from @typ4 's website.



Rock

 

[Farmer Rock]

Thanks for responding Rock, it only has issues getting started. When running, it runs perfectly! Can't remember exactly but it's only been in the last year or so that Ive had this issue. I used to be able to throttle it after initial startup and keep it running but now it starts up, surges and dies! And only after cranking and bleeding through the shrader valve can I get it started

Ok, so it is just drain back then. It could very well just be a pinhole in a fuel line. Being that a diesel fuel system in proper condition will hold constant pressure in the lines no matter how long it sits, but if you get a pinhole (or some other air leak), it won't maintain the pressure, the fuel will flow back down to the tank.



Rock

 

[Craig58]

Thank you for sharing your knowledge. I sincerely hope I can find the issue, I love the truck!

 

[Farmer Rock]

Thank you for sharing your knowledge. I sincerely hope I can find the issue, I love the truck!

I'm glad I could help in any way! I am sure you will find the problem.


Rock