Bringing back to life a 2009 HMMWV M1165A1 from GovPlanet - total newbie, please help...

[T9000]

There are 2 bolts inside by the end of ebrake handle(when down). Those hold the fuel filter to firewall. It is easier to get the canister out if you remove the 2 hoses at top, from inside the truck.

Found them! That was great info! Thank you! Definitely there is something going on with the fuel filter, the moment I removed the two bolts and tried to move it around, it started to leak from the bottom, and it goes to the theory that air is getting into the fuel system.
I don't know if the pump is supposed to come out from the top, but there is where I pulled it from, between the engine harness, the ground cable that goes right above it, the oil check stick and the purple acceleration cable that constantly gets in the way, but it's out! I hope I can put it back in
And there is a cut in the bottom tubing, which I will replace.



Does anyone know where the 4 wire connector should plug in?

 

[T9000]

Welcome to the hobby! When I bought my M934 from GP, it had been sitting for eight years . We prepped the truck for the 1,000 mile drive home. It ran pretty bad for the first couple hundred miles. As we kept filling it with fresh fuel and additives it ran better and stronger. By the time we made Michigan, it was running up hills without slowing down much at all. I would suggest putting fresh fuel in it then take it for a few hundred mile road trip. If your nervous about that, ask a friend to follow along in a chase vehicle…

Yes, I did fill up the tank with fresh diesel and drove it around for about 50 miles or so, some on the freeway at 80mph (maxed out the spedometer, didn't check with the GPS yet), thinking like you said to get things to loosen up. The engine sounds a lot better with a lower tone than before, the only real issue remaining the up and down RPMs while idling and occasional stalling with tough to start. It starts much faster if I restart it soon after it stopped (once it died at a stop light and restarted right away, that's why I keep the throthle lock at around 900rpm when driving around).

 

[T9000]

The windshield fluid tank is also disconnected with no cable or connectors visible for reattachment, but also nothing seems to be cut (besides the one wire I mentioned earlier) so could it be a whole harness missing? Maybe that would connect to the fuel sensor as well?

 

[T9000]

You’re not asking dumb questions. That’s not a problem here. Helping new members is what we do. At some point you are going to see that you landed on one the best sites for any hobby. I don’t know much about your HMMWV so I won’t be much help except to tell you that you are getting real good advice from folks that do!
I’m glad you are changing the fuel filter. You may have to do it again after you get some miles on it. when these trucks sit for some years it can take a while to get things loosened up and working properly. Bouncing down the road may free up some crud in the fuel system. You are doing the right thing by changing filters.
I like my charge voltage around 27 volts. That is measured with a digital volt meter. The two volt ripple might add one volt at the peak. Putting a scope on it was a good call. I’ve never thought to do that ( I will now).
I hope someone has a trick for removing the fuel filter that doesn’t require removing the dash!
How are the breaks? First we make them stop, then we make them go, then we go after the small stuff…
Spending this time now will ensure you have lots of SAFE fun later. Press on.

PS. Thanks Action! You were answering the fuel filter question at the same I was asking about it. This site has MIND READERS!

The breaks seems to work normally, didn't check it specifically yet besides trying to stop hard and seeing that they hold well, but they are on the list, right now I am obssesed with the engine issues The truck showed about 7,000 miles which I tend to believe they are real because the origianl oil filter is marked as being changed at about 6,000 miles in 2012 and the tach had about 800 hours - statistically is very improbable that all three are misleading, but not impossible. The radiator also seems very clean, the pedals are not worn out or other signs of high wear that would indicate the truck being a higher mileage.
I appreciate very much everyone's input and hope to join in some local or regional meetings if anything is happening!

 

[T9000]

Your symptoms are consistent with air in the fuel supply. You also mentioned a fuel leak. That is where air could enter the fuel supply. I'd fix that and change the fuel filter. Read up on how to bleed the fuel system.

Thank you! I am going with that premise for now, and as I removed the fuel filter there was another cut/ leak in the water release line.

The main leak seems to come from the fuel pump line itself, maybe on both sides, hopefully not from the fuel pump, which appears to be dry:

 

[mgFray]

The windshield fluid tank is also disconnected with no cable or connectors visible for reattachment, but also nothing seems to be cut (besides the one wire I mentioned earlier) so could it be a whole harness missing? Maybe that would connect to the fuel sensor as well?

View attachment 850723

Wires should have a grommet on them, with a corresponding hole to go into cab, under the dash.

Should be two wires there to connect it to.

 

[T9000]

Wires should have a grommet on them, with a corresponding hole to go into cab, under the dash.

Should be two wires there to connect it to.

Got it! I think I found the hole, it's the only one around the tank, and the grommet looks like it would fit in. I will look for the matching connectors on the other side. Thank you!



Any idea where the 4 wire connector from the fuel filter (picture below) should go?

 

[mgFray]

Got it! I think I found the hole, it's the only one around the tank, and the grommet looks like it would fit in. I will look for the matching connectors on the other side. Thank you!

View attachment 850742

Any idea where the 4 wire connector from the fuel filter (picture below) should go?

View attachment 850745

Mine just has a connector on the harness right there. But it’s only used by the diagnostic port in the cab, so not hooked up should be fine.

 

[T9000]

Mine just has a connector on the harness right there. But it’s only used by the diagnostic port in the cab, so not hooked up should be fine.

That's good news, with all the fuel system issues I am having, I didn't want to leave anything unchecked, and now that's one less thing to worry about, Thanks!

 

[T9000]

Just a quick update on the fuel filter and water separator...the fuel filter is busted on the outside but the water separator seems OK, not very dirty, which should be good news for the IP from what I read around the forum.





I am also looking to replace the two inline filters, I read something about fuel tank send/ receive lines and need to find them, after which will do the air purge,
The way I understand it from the manual, it says to disconnect the output fuel filter line that goes to the IP and crank the engine until the diesel starts to flow out of the fuel filter and reconnect the line.
However I did see a comment by RetiredWarHorses saying "pull the drain back line of the front of the pump while it is running" - sorry, which line and which pump? The IP?

 

[Retiredwarhorses]

Just a quick update on the fuel filter and water separator...the fuel filter is busted on the outside but the water separator seems OK, not very dirty, which should be good news for the IP from what I read around the forum.

View attachment 850749

View attachment 850750

I am also looking to replace the two inline filters, I read something about fuel tank send/ receive lines and need to find them, after which will do the air purge,
The way I understand it from the manual, it says to disconnect the output fuel filter line that goes to the IP and crank the engine until the diesel starts to flow out of the fuel filter and reconnect the line.
However I did see a comment by RetiredWarHorses saying "pull the drain back line of the front of the pump while it is running" - sorry, which line and which pump? The IP?

the fuel filter is not busted…that’s how they are right out of the box, doesn’t affect function.

 

[T9000]

the fuel filter is not busted…that’s how they are right out of the box, doesn’t affect function.

I was just comparing it with the new one I installed and actually that's very good news for the IP.

Regarding purging the air in the fuel system, I noticed a screw on top of the fuel output line from the fuel filter, could I use that to let the air out while cranking the engine and tighten it once the fuel starts flowing out?
Should I remove connector 54A (to prevent the IP running without fuel - I read something about not being good for it to run without fuel?) during this procedure to and reconnect it after the fuel made it past that point?

 

[Action]

The IP rotates when the crankshaft and camshaft rotate. Via a chain. You cant unplug a wire to stop that.

 

[T9000]

Ok, I have been doing a lot of reading on the forum and read about 54A being unplugged from the IP, but from looking at the schematics it looks like 54A powers the fuel solenoid, so please disregard that comment.
How about using the screw on top of the fuel filter to purge the air? Is that a good way? Or what would you recommend?

 

[T9000]

The IP rotates when the crankshaft and camshaft rotate. Via a chain. You cant unplug a wire to stop that.

Ok, I have been doing a lot of reading on the forum and read about 54A being unplugged from the IP, but from looking at the schematics it looks like 54A powers the fuel solenoid, so please disregard that comment.
How about using the screw on top of the fuel filter to purge the air? Is that a good way? Or what would you recommend?

 

[Gamble]

The issue is most likely your check valves at the rear passenger side of the truck. They are 2 brass fittings in the fuel lines. Your problem is identical to what I was experiencing. Delete the check valves and run a hose between both sides where the valve used to live. Use the existing clamps to clamp it down. That should eliminate your issue.

 

[T9000]

The issue is most likely your check valves at the rear passenger side of the truck. They are 2 brass fittings in the fuel lines. Your problem is identical to what I was experiencing. Delete the check valves and run a hose between both sides where the valve used to live. Use the existing clamps to clamp it down. That should eliminate your issue.

Are the two check valves looking like these?

Is it OK if I replace them instead of bypassing them?
I am looking to find them.

 

[Action]

Are the two check valves looking like these?
View attachment 850854
Is it OK if I replace them instead of bypassing them?
I am looking to find them.

That is not the check valve. That is a vent that sits behind the radiator overflow tank.

 

[Gamble]

These are the check valves once they are removed. They are NOT fun to get out but it is doable.

 

[T9000]

These are the check valves once they are removed. They are NOT fun to get out but it is doable.

Got it! I appreciate it! If I understand this correctly, you are saying to remove them to see if it fixes the problem, but then eventually replace them with new ones?

BTW, your truck looks very good, what tires do you have on, 40/13.5?