HELP!

[WillWagner]

The Museum was gifted a, depending what you look at, either a 2009 or 2012, M1123. Story goes that it was driven around for a bit, the guys kid took it down the hill from the house, fueled it, and started to drive back, it stuttered and died. To me, sounds like it was ran out of fuel. This happened 2 years ago. It was towed to their house and has sat.

Fast fwd 2 years. We go out to this guys house to look at it. Crank, no start, no smoke. Attempted a few things but the batteries were way low, so we opted to have it towed home.

Went to the museum today and got it pushed around into the shop and started in on it. First thing, pulled the level sender, the tank is fugly. Removed the filter, it is absolutely new, very little fuel was in it. I do think it has been run dry.

I removed the line at the tank and blew from the tank to the filter inlet, maybe 1/2 cup of fuel came out. Not as bad looking as what is in the tank, but still ugly. Hooked a line from the fuel tank metal line to a clean can of new diesel. Put the filter back together, removed the bleeder and got fuel to the filter by pressurizing the can. Oh yeah, the check valve at the filter was stuck open. took it apart and cleaned it out, works as it should. Clean fuel out of the bleeder. Closed it, cracked some lines and proceeded to crank it. No fuel from the pump. I removed the return from the pump and get a small amount of fuel from that. I also pressurized the fuel can as I was cranking, still no delivery. There is battery/cranking voltage at the wire going into the top of the pump, I THINK that is the shut down solenoid, if not, point me in the right direction.

I get it that these......things......wont light if the GP system is not operating, but, there should be fuel delivery from the pump. I have zero smoke out the pipe of any type. What am I missing?

I just gotta say, these things are f-ing stupidly put together! Who in their right mind makes a tactical vehicle that has a fuel filter, the FIRST thing that makes a running engine not want to run, tucked up under things, secured in a fashion that takes two hands to get a bolt out, clamped on hoses that need removing to get at the most basic and easily compromised part of the fuel system!?

I would rather work on a tank or a bulldozer than one of these!

 

[NDT]

When the HMMWV came out in '84, it just had the puny 60A alternator which allowed more room to work on the filter. The injection pumps on these go bad at roughly 10 year intervals. If you have ample fuel pressure, 24 volts to the solenoid, and it's clicking back and forth inside, probably time for an overhaul.

 

[WillWagner]

The truck was OVH, by USMC, dunno, '09 or '12, but there are less than 100 miles on the pig.

 

[86humv]

The 2 check valves down by the tank should be removed....the larger hose one is feed line and it usally causes
the no fuel issue.
Put in two longer hoses and be done with that.

 

[WillWagner]

The 2 check valves down by the tank should be removed....the larger hose one is feed line and it usally causes
the no fuel issue.
Put in two longer hoses and be done with that.

Where would said check valves be located, exactly? It looks like the lines are hard from where they leave the tank, up to where it goes from the frame mounted hard line to the little 6 inch rubber line connected to the lift pump. There are 4 lines at the tank. I am kinda messed up now, it is tough for me to get under things and work on them, my neck gets all swelled up. There is a check valve at the inlet of the filter. It was stuck open. This is a 2009, I am assuming. Were the check valves re located as the years went on and the one up at the filter is the one referenced in the supply line? The one at the filter makes sense to me, it being there would prevent fuel from draining back to the tank from the filter back.

I do have flow from the tank, using a small amt of shop air. Go juice into and out of the filter. That is just with the switch on. I did find out that if the switch was not on, there was no fuel coming out of the filter. Is the electric deal on the outlet of the filter top some sort of shut off? I did not check to see if there is fuel while cranking coming out of the filter.

I just want to see some type of smoke out the tailpipe, fuel delivery to the injectors. Right now, there is none of the above.

And another stupid HMMWV thing. WHY put a hole in the bed over the fuel pick up that isn't big enough to get the damn thing out? Who does that? Guess someone's retarded nephew needed a job. "Here, you go cut a hole right HERE in all theses trucks"

 

[98G]

Where would said check valves be located, exactly? It looks like the lines are hard from where they leave the tank, up to where it goes from the frame mounted hard line to the little 6 inch rubber line connected to the lift pump. There are 4 lines at the tank. I am kinda messed up now, it is tough for me to get under things and work on them, my neck gets all swelled up. There is a check valve at the inlet of the filter. It was stuck open. This is a 2009, I am assuming. Were the check valves re located as the years went on and the one up at the filter is the one referenced in the supply line? The one at the filter makes sense to me, it being there would prevent fuel from draining back to the tank from the filter back.

I do have flow from the tank, using a small amt of shop air. Go juice into and out of the filter. That is just with the switch on. I did find out that if the switch was not on, there was no fuel coming out of the filter. Is the electric deal on the outlet of the filter top some sort of shut off? I did not check to see if there is fuel while cranking coming out of the filter.

I just want to see some type of smoke out the tailpipe, fuel delivery to the injectors. Right now, there is none of the above.

And another stupid HMMWV thing. WHY put a hole in the bed over the fuel pick up that isn't big enough to get the damn thing out? Who does that? Guess someone's retarded nephew needed a job. "Here, you go cut a hole right HERE in all theses trucks"

Be glad you have the access panel retrofit in the bed. Otherwise you'd be dropping the tank...

 

[Coug]

The check valves are in the hard lines, physically located just in front of the fuel tank. There is a transition from the hard lines on the tank, to the hard lines that run along the frame rail of the truck. The check valves are between the two sets of hard lines. As was mentioned, remove the check valves and just bridge the space with the rubber fuel line.
I believe that you can see them looking up from underneath the truck, but everything is kind of dark down there and blends together.

 

[86humv]

If the truck is a true m1123 it will have the 2 check valves by the tank unless someone already removed them....
The check valve up at the filter is ok to leave in...its a weak one and should not fail closed.

 

[WillWagner]

If the truck is a true m1123 it will have the 2 check valves by the tank unless someone already removed them....
The check valve up at the filter is ok to leave in...its a weak one and should not fail closed.

Very good, I will check that out.

The valve at the filter was all gummed up.

 

[WillWagner]

Be glad you have the access panel retrofit in the bed. Otherwise you'd be dropping the tank...

Still have to to get at the sock on the pick up. The tank is full of some nasty stuff. You know what old cooking oil gets like, all sticky? Well, the tube for the level sensor has that kind of stuff on it. You gotta love California fuel.

 

[Guyfang]

You could not pay me to accept one of those trucks, for free.

 

[WillWagner]

With the location of the problematic check valves solved, on my end at least, there still is an issue with zero fuel delivery from the pump to the injectors running....but not returning....from an isolated fuel source.

There is some sort of electric valve on top of the fuel filter. I did find that if the ign was off, no fuel would come out of the filter. Switch on, fuel flows.

What is that device for?

I think I will remove it and see if fuel is delivered, possibly some sort of control issue causing the valve to close when cranking?

These are just a mechanical engine with some sort of electronics laid on top of them, correct? I have ground hopped one of these and it started, ran, throttled just fine. Guess it could be possible that the pump is junk, but the inside of the filter and housing was squeaky clean, nothing like what the tank is full of.

 

[swbradley1]

I question the value of making any tactical vehicle more complex to build or maintain than a Deuce or M809 Will.

 

[NDT]

The “valve” on top of the fuel filter is the pressure transducer for the STE/ICE. You can get rid of it.
The residue fuel in the injection pump is the same nasty crap as in the tank, my guess is the pump passages are gummed up and blocked. Send to overhaul.

 

[Retiredwarhorses]

I question the value of making any tactical vehicle more complex to build or maintain than a Deuce or M809 Will.

those old POS beat the crap out of you, fatigue was real just in the simple operation of those old vehicles.
I lived it first hand over 30yrs in the military and as the owner of an M series restoration and repair shop.
But i see your point

 

[98G]

Still have to to get at the sock on the pick up. The tank is full of some nasty stuff. You know what old cooking oil gets like, all sticky? Well, the tube for the level sensor has that kind of stuff on it. You gotta love California fuel.

Been there, done that. Copious rinsing from the top while sending compressed air retrograde down the hardlines solved my issues.

FWIW, i think @NDT has your answer.

 

[KKroger]

I'll ask... Are you gettting fuel PAST the filter housing. to the center line on the Injector pump (or just getting past the filter housing?? Turn the switch on and then plug unplug the fuel shutoff solenoid and see if it clicks

 

[BLK HMMWV]

I kept telling you about the check valves.
I'm surprised you haven't mentioned the Lamborghini mechanic yet .
What kind of switch is in this thing ? A keyed one or the original 3 lever?
Also have you cracked an injector line?
And you mentioned when you first went to recover it you tried many times but the batteries where not fully charged . Hopefully you didn't smoke the Magic box under the dash below the windshield washer bottle.
Was there standing water in the valley below the IP.
Does the bottom of the IP look rusty.
What's the # on the tag on the wire going to the IP.
You can always take it back to the Lamborghini mechanic. Oh sorry!!
I know I'm stirring the pot again and not helping.
And knowing that kid you sure he actually put Diesel in it and not Flex fuel?
I'm going to go make some popcorn now.

 

[BLK HMMWV]

And you did verify it had a CDR valve on it. Because you had told me some of the fording system had been removed that was a common demill thing but normally they took the CDR valve.

 

[BLK HMMWV]

Some times people also put a hidden cut off switch in funny places. Just for fun look under the big screw off cover to the STE/ICE plug to the right of the shifter.