Humvee won’t start after steep hill

[tauteur]

I was climbing a steep hill, with less than a quarter tank. Engine died. Let humvee slide to flat ground. Wouldn’t start. Battery died trying to start.

charged batteries, few days later, put 5 gallons of diesel in, thinking maybe low on fuel. Fuel gauge reading near E. Cranks, but won’t start.

checked fuel filter, sucked fuel through it. Took fuel filter off, put thumb on end of electric fuel pump (put an electric fuel pump on after mechanical one failed) - engine started and ran with thumb on fuel line, past filter. Then engine died. Tried this again, no luck. Fuel pump doesn’t seem to be sucking. Fuel filter fills up slowly, or not at all, yet when I suck end of fuel filter with mouth, it fills up quite easily. Batteries died again trying to start.

Now charging batteries again, probably need new batteries

and asking for advice

 

[Mogman]

I am confused, are you trying to run the engine with the fuel line disconnected? That seems to only way it could "run" with your finger on the end of the fuel line.
with an electric pump you should have good flow or you should not even try to run the engine, also you need good batteries at all times, ether you are cranking it too much risking burning out the starter or your batteries are shot, again with an electric pump you should require very little cranking.

 

[tauteur]

I am confused, are you trying to run the engine with the fuel line disconnected? That seems to only way it could "run" with your finger on the end of the fuel line.
with an electric pump you should have good flow or you should not even try to run the engine, also you need good batteries at all times, ether you are cranking it too much risking burning out the starter or your batteries are shot, again with an electric pump you should require very little cranking.

I was testing to see if there was suction coming from fuel pump, which when I started it like that, it was the only time it started …

 

[Mogman]

Are you saying fuel pump or injection pump (IP), you should never try to start it with no fuel going to the IP which cannot happen with a line disconnected.

 

[tauteur]

Are you saying fuel pump or injection pump (IP), you should never try to start it with no fuel going to the IP which cannot happen with a line disconnected.

fuel pump. I disconnected the fuel filter, before the fuel pump, to clean fuel filter , check for clogs, see if fuel pump was sucking … it wasn’t sucking so much, barely - not enough to fill fuel filter - wondering if that’s due to low battery

 

[Mogman]

Please post some pictures of your fuel system.
The filter should be after the pump.

 

[Barrman]

Most electric pumps like to push fuel. They really don’t suck fuel very well in comparison.

Here is a video I did after pretty much your exact same scenario showing how long it takes to reprime the injection pump with a pusher electric pump. Different truck but same engine:

 

[tauteur]

I’ll get pictures tomorrow. I actually got the truck started. Drove it 3 miles. Then it started bogging down and dying every 100 yards or so. See a previous post about overheating. It’ll drive fine for 3 miles but then when it heats up, it can’t stay running or keep power. The fuel filter does come before the pump however…

was gonna try and see what the return line looks like, after reading people having similar issues. Bought it from GovPlanet 2 years ago - drove it 2 hours home no problem. Then fuel pump went out. Put new fuel pump in, same problem. That’s when we put in electric pump. Then soon after noticed it overheating and dying out. Someone thought maybe transmission overheating, but I think I read that that wouldn’t be the case on this truck.

 

[Mogman]

Sounds like a fuel starvation issue, how do you know it is overheating?
BTW most diesels will run until they melt down, not simply stop running.
It could possibly be a return issue. but more likely a starvation issue or possibly a vent issue, did you remove the check valves in the suction and return lines?

 

[tauteur]

Sounds like a fuel starvation issue, how do you know it is overheating?
BTW most diesels will run until they melt down, not simply stop running.
It could possibly be a return issue. but more likely a starvation issue or possibly a vent issue, did you remove the check valves in the suction and return lines?

I say overheating because it only happens after it’s been driven for a while. When it’s cold and fresh it runs fine

I’m not familiar with the check valves in the suction and return lines

 

[Mogman]

It likely has nothing to do with engine heat.
If you have a return line issue it can take some time at speed to cause fuel starvation. (when the fuel pressure in the body equalizes with the transfer pump in the IP, the high pressure head actually starves for fuel)
If you have a fuel tank vent problem it can take time at speed to cause fuel starvation. (you can try and run it with the fuel cap loose)
If you have a cheap fuel pump it can cause fuel starvation. (a good electric pump will set you back $150-300)
Trying to pull fuel from a partially plugged filter or stuck check valves can cause fuel starvation
There are two check valves directly in front of the fuel tank in the fuel lines, they should be the very first thing that gets removed or you can think you have multiple fuel pump issues, you will need some 3/8 and 5/16" high quality rubber fuel hose to get them out of line.
As Barrman said pumps like to push fuel better than suck this is one reason you should put the filter after the pump, also you want the filter to be the last thing in line to protect the IP in case the fuel pump fails and send stuff downstream.

 

[TOBASH]

Perhaps a bad lift pump.

 

[Hummer Guy]

Sounds like the fuel pump is too weak.

 

[bbailey]

What is the equivalent of the pink wire on a 2013 1097 hmmwv? Can somebody point it out in a screenshot

 

[TOBASH]

Pink wire???

 

[Milcommoguy]

Pink wire is the color Ford uses on fuel pumps...most of the time.

Or it could be Barbie's rig, CAMO

 

[Mogman]

I think he is talking about the run signal to the IP, pink is what GM used on the civy engines, I still see it from time to time in my 5.7L nightmares
Welcome to the SS forums
If the run wire to the injection pump is what you are talking about it is the wire towards the front of the IP (towards radiator) and has a wire tag with the number 54 on it.
All the wires on a Humvee are black. (well there are some exceptions)

 

[Milcommoguy]

That's true on the CUCV's too. Solenoid control.

Guess pink the new #54.

You getting this Ken., CAMO

 

[TOBASH]

Pink is the new orange is the new black. Who knew CamO

 

[bbailey]

That's true on the CUCV's too. Solenoid control.

Guess pink the new #54.

You getting this Ken., CAMO

Wire 54 helps me..thanks