2003 Cummins refuses to start unless it's plugged in.

[Psbrubaker]

My 03 Dodge Ram 2500 Cummins absolutely refuses to start unless it has been plugged in, even if it's in a garage where it's kept at 60 degrees all night.



Background: I have a FASS fuel system. When I turn the key on, the FASS pump kicks on and starts running and doesn't quit after a few seconds like it used to. I'm suspicious i'm not getting the necessary starting fuel pressure, possibly from a leaking injector.



The heating grids have been tested and are working fine.



One weird thing, when the bolt on top of the fuel pressure relief valve is removed, the truck will start right up. However even that doesn't work if the engine is really cold--30 or below.



Anway, thought I'd throw it out to the TDR community in the hope that you all could steer me in the right direction. Any help would be appreciated!

 

[JJPage]

Sounds like a rail pressure problem for sure. Your rail relief valve could be operating open, and not closing back off, once it's running it is able to hold enough pressure to stay running but will not restart. When you remove the banjo bolt from the top of the valve, you must be disturbing it enough to close... or you are bumping your rail pressure sensor...



I'm having a rail pressure problem myself right now, and there can be alot of contributing factors, cross tubes, injector(s) body or tip, CP3 components.



You can try capping your rail with a solid bolt and neoprene washer in place of that banjo bolt, see if it solves the issue, if it does, replace the valve.

 

[Psbrubaker]

I did put a pressure relief bypass valve on, and that didn't solve the problem.

 

[jray]

Background: I have a FASS fuel system. When I turn the key on, the FASS pump kicks on and starts running and doesn't quit after a few seconds like it used to. I'm suspicious i'm not getting the necessary starting fuel pressure, possibly from a leaking injector.

Not sure I understand this part. The FASS should be running all of the time while the engine is running. Unless you're talking about a pre-start condition. If its a pre-start condition I believe the pump will cycle the second time you attempt to start for 20 seconds.

 

[Psbrubaker]

Yes, I was talking about a pre-start. The first time you turn the key, before engine start, my FASS used to run for a just a few seconds and stop. Now it runs non-stop anytime the key is turned on, running or not.

 

[JJPage]

Chrysler released a flash allowing the lift pump to run longer, quite some time ago. I think mine runs for about 30 seconds now before stopping.



I would re-torque your cross tubes next, least expensive exercise at this point. If you go to forums, and click on "5. 9 engines and transmissions", there is a Sticky at the top, that Member sag2 compiled. It is a complete "how to" with pictures, as good or better instructions as you will find anywhere.



You may get lucky with only doing this, but it has to be eliminated as a possible cause of rail pressure loss.



Sorry, it's not there..... I know I saw it somewhere, if nobody else can link it ,I will when I get back to my computer.

 

[JJPage]

There you go!



https://www.turbodieselregister.com...148621-injector-install-procedure-photos.html

 

[rbattelle]

Chrysler released a flash allowing the lift pump to run longer, quite some time ago. I think mine runs for about 30 seconds now before stopping.

This is true. Older trucks run the pump for 2 seconds pre-start (it goes off when the WIF bulb test goes out).



They later changed the programming to engage the LP for 30 seconds. So if your truck has been flashed, that explains the LP behavior.



Ryan