HMMWV Crank No Start

[emndive]

Hi All,
I apologize as I know these are frequent Posts (and I have read them all). Our FD just got a surplus HMMWV and I have been having a crank no start issue since we got it. It will crank all day long and put out white smoke out of tail pipe. I have good fuel pressure at injectors. The glow plugs were spent so I replaced those. Confirmed getting 24V at plugs. Swapped out temp sensor (coolant) on top of engine with one from another truck. (batteries were disconnected prior to swap). It appears to have a newer EESS (yellow label Nartron). I added the suggested "spider" ground set up to the chassis and components. New batteries installed. The wait to start light stays on for 10 seconds goes off and truck cranks but will not start. I added a block heater and even warmed this thing up with a salamander heater with no luck. If I take a heat gun to the coolant temp sensor and warm it up the WTS light only stays on for a second which tells me that sensor and the EESS is working properly. Suggestions...?

thanks guys

 

[Dock Rocker]

Have you Ohm’ed the glow plugs to make sure that they are making heat?

Your GP control box may be your issue. I believe that the newer box it the green label and the yellow label box is the old version.

My guess is that your new GP’s are already toast.

Don’t forget to get the matching sensor for the new control box and unplug the batteries before you do anything with the box or glow plugs.


Sent from my iPhone using Tapatalk

 

[ikoinu]

As long as it's not ridiculously cold out, the block heater should make up for bad glow plugs and allow you to start in my experience. White smoke, so looks like you're getting fuel.

 

[Keith_J]

With NATO cables and 80 F weather, it should start without functional glow plugs. Feel the GPs to see if they are heating, if you put 12 volt GPs in, they are gone.

What starter? 27 MT or 28 MT? The 28 is gear drive, the 27 is direct drive, larger and uses series wound field while the 28 uses permanent magnet field so it tends to spin faster. Either will get slower as it ages, an old starter in a worn engine will not start with failed GPs. You need at least 200 RPM crank speed.

 

[Gear Report]

From what you listed having done, it sounds like the start box and GPs are working correctly... or were, at least.
But I don't see any mention of verifying you are getting fuel to the cylinders.
I would work through the startability test flowchart mentioned in this article:
https://gear-report.com/help-hmmwv-wont-start-humvee-glow-plug-start-system-maintenance

 

[TOBASH]

If you have a weak fuel pump and your fuel is less than half a tank, you might not start.

If there is air in the system you might not start.

Is the fuel gauge working? Do you have at least half a tank?

Just spitballing, 'cause you seem to have many of the bases covered.

???