HMMWV hard starting. Can't figure it out please help

[MarkM]

Been having big problems for a while now with my truck. Old GP controller failed. List of new parts. New controller, New glow plugs, New coolant temp sensor for FI advance, New engine wiring harness, New grounding kit, New controller box GP sensor, New fuel filter, New batteries. Glow plug light comes on for around seven seconds and when I try to start the truck it takes a long while 30 seconds or more to slowly start. Smoke coming out tailpipe. Seems like maybe a fuel delivery issue at this point like I am not getting fuel pressure or air in the system. Once running it runs fine and starts right back up. Once hot when starting the GP light flashes and then starts right up.

When I changed the fuel filter and bled the system it started right up when cold. This issue is getting very old. The fuel drain petcock does not drain fuel when the truck sits and I seem to remember it did before. Could the fuel be being sucked back to the tank? It is acting like a carbed gas engine that has sat for a while and the fuel in the carb has evaporated and makes for hard starting. At my witts end here guys. Please help as I have very little hair left to pull out.

Mark

 

[Retiredwarhorses]

Why would you open the water seperator when not running? You want to purge the water and debris while you have fuel pressure. Have you checked you fuel pump? You should have a good stream of fuel from the water seperator
when running “assuming drain hose not clogged”, if not, tells me the fuel pump is bad.

 

[MarkM]

I have thought the fuel pump may have issues and I have ordered a new fuel pump as well as an inline pressure gauge and new fuel line hose. Only checked the drain to see if the system is holding pressure. Thank you for the reply.

Mark