2003 1078 A1 derated ether start

[MGVFD]

Hello,

Our VFD received this truck just a little bit ago through a DOD grant. Truck ran and drove fine. The kids at the HS painted the truck. They didn't do anything engine wise just the cab and bed.

The truck wouldn't start today without either. Even then it wouldn't stay running. We lifted the cab and primed the fuel system and the truck started. It stayed running, but the check engine light was flashing once every ten seconds. The truck wouldn't go over ten mph. We are looking for someone with a code reader. I think the fuel problem may be the fuel feed line bleeding off. If you let the truck sit for tens or so you'll have to prime it again.
The batteries were low. We had to jump start the truck. The alt had the two green lights and the voltage gauges read good voltages.
Thank you for any input.

 

[fuzzytoaster]

Check the following:

1. All 3 soft fuel lines for cracks
2. Visually check for wetness on fuel filter and fuel/water separator
3. Remove separator bowl and inspect plastic bowl for cracks, fatigue, etc as well as condition of o-ring
4. If able, prime the fuel system with no more than 5 psi of air and inspect fuel system for leaks, hissing, etc (black primer bulb especially)

I'm in DFW and have the ability to read codes. My semi is dropping off a 5 ton in Sulphur Springs, TX on Monday next week. He could bring it back to my shop for inspection and etc. There may be more going on since you said it only does 10 mph which is odd. Typically bad fuel delivery leads to no start situations, not slow driving.

 

[GeneralDisorder]

Just replace the fuel hoses - they are rotten and sucking air. This is real common on surplus FMTV's.

 

[Ronmar]

What fuzzy said, the bleed-down of the primary fuel system indicates a leak somewhere. If it is leaking it IS sucking in air! There is a primary fuel pressure test port between the HEUI pump and the filter on the side of the head. sucking air will show as dips/fluctuations in primary pressure.

you will need a reader to diagnose the Check engine light, but it may be related to a missfire/rough run/hampered ability to maintain commanded RPM with the inputs the ECU is giving to the injectors Ect.

baseline fuel pressure is the foundation of engine performance. Always surprised that most EFI systems don’t even monitor it…:0

here is what an air leak looks like on a primary fuel gauge. Pressure should be steady, 25@ idle ramping up to 60PSI by peak torque RPM. If yours is leaking down in minutes it will look a whole lot less stable than this video I think…