HMMWV starts then stalls

[Gary the dog]

I have an M1097R1 with a NA 6.5l that starts easily then stalls after about 2 minutes and will restart in about 1 hour with same result. It will NOT immediately restart.
It has heavy fuel smelling white smoke as it idles. Here’s what’s been done so far. I would appreciate serious recommendations for remedy.
1. New glow plugs
2. New injectors
3. Fuel tank removed, cleaned and reinstalled
4. Fresh fuel.
5. Fuel line check valves removed, cleaned, checked for operation and reinstalled in correct direction.
6. Fuel lines removed, cleaned, with high pressure air and reinstalled.
7. New nartron smart start control box.
8. Motor has no blow by at oil filler tube when running.
9. Batteries show full charge.
10. Alternator checked and is charging properly.
11. Injection pump fuel bowl is clean and shows no corrosion, tarnish or discoloration when removed top cap.
12. Fuel pump output meets specs pre filter and post filter.
13. Fuel solenoid operates correctly in injection pump.
14. Cold start solenoid checks out correctly according to technical manual.
15. White, fuel-smelling smoke, fills the area when motor is running.
16. Fuel lines cleared of air.
17. Removing fuel tank cap makes no change.
18. Idles smoothly until it dies
19. Engine will rev while it’s running.
20. solenoid will still operate after engine stalls.
21. Starter will still turn engine, at proper speed, after engine stalls.
22. Glow plugs are still good.
23. Same result with different control box.

I’m puzzled right now and kinda stuck.
Thanks for reading and offering any useful ideas.

 

[Dieselmeister]

I have an M1097R1 with a NA 6.5l that starts easily then stalls after about 2 minutes and will restart in about 1 hour with same result. It will NOT immediately restart.
It has heavy fuel smelling white smoke as it idles. Here’s what’s been done so far. I would appreciate serious recommendations for remedy.
1. New glow plugs
13. Fuel solenoid operates correctly in injection pump.
14. Cold start solenoid checks out correctly according to technical manual.
15. White, fuel-smelling smoke, fills the area when motor is running.

More questions than answers.

Does it idle smooth, or is it missing on some cylinders? White smoke = unburnt fuel.
Can you rev up the engine while it's running?
If yes, will it run for the same amount of time at high rpm as it does at low rpm or does it die sooner? (Possible fuel problem)
Will the fuel solenoid click after the engine dies (within the hour that it wont start)? (Possible electrical problem)
Does it crank but not start, or no crank either? (Electrical problem)
Are the new glow plugs still good?
Some new control boxes may be bad.

 

[Gary the dog]

I have an M1097R1 with a NA 6.5l that starts easily then stalls after about 2 minutes and will restart in about 1 hour with same result. It will NOT immediately restart.
It has heavy fuel smelling white smoke as it idles. Here’s what’s been done so far. I would appreciate serious recommendations for remedy.
1. New glow plugs
2. New injectors
3. Fuel tank removed, cleaned and reinstalled
4. Fresh fuel.
5. Fuel line check valves removed, cleaned, checked for operation and reinstalled in correct direction.
6. Fuel lines removed, cleaned, with high pressure air and reinstalled.
7. New nartron smart start control box.
8. Motor has no blow by at oil filler tube when running.
9. Batteries show full charge.
10. Alternator checked and is charging properly.
11. Injection pump fuel bowl is clean and shows no corrosion, tarnish or discoloration when removed top cap.
12. Fuel pump output meets specs pre filter and post filter.
13. Fuel solenoid operates correctly in injection pump.
14. Cold start solenoid checks out correctly according to technical manual.
15. White, fuel-smelling smoke, fills the area when motor is running.
16. Fuel lines cleared of air.
17. Removing fuel tank cap makes no change.
18. Idles smoothly until it dies
19. Engine will rev while it’s running.
20. IP Solenoid will still operate after engine stalls.
21. Starter will still turn engine, at proper speed, after engine stalls.
22. Glow plugs are still good.

I’m puzzled right now and kinda stuck.
Thanks for reading and offering any useful ideas.

 

[Gary the dog]

Idles smoothly until it dies
Engine will rev while it’s running.
IP Solenoid will still operate after engine stalls.
Starter will still turn engine, at proper speed, after engine stalls.
Glow plugs are still good.

this info has also been added to original post. Thanks for the questions.

 

[155mm]

I would start at fuel filter housing with a good inspection of the back ear, next i would bypass filter with one of the clear filters and you can check for air in the line also.

Mechanical fuel pump failure? Are you growing oil in crankcase?

are you getting good return fuel flow to ip

 

[TOBASH]

I posted about a similar problem. Disconnect your exhaust and see if the problem goes away. If that’s the case, then your catalytic converter is clogged. These vehicles have huge problems with the catalytic converters like a clogged during prolonged idle. The military likes to idle their trucks which clogs up catalytic converters. If the converter is dirty, there are many described methods to clean it however, you can always spray it with high intensity, degreaser on the engine side and let it sit, and then blow water through it on the exhaust side.

 

[Retiredwarhorses]

sounds like you have the cold advance and fuel cutoff wires reversed at the top of the pump, the rearward plug is “ribbed” to match the injection pump ribbed boot, 54A is the fuel cutoff solenoid and is the forward plug.
when the truck warms up, it denies 24v on the cold advance thermostatic switch on the right rear head this kill your fuel cutoff solenoid off solenoi, the temp has to drop before voltage will reappear, just swap the 2 wires.

 

[Retiredwarhorses]

I posted about a similar problem. Disconnect your exhaust and see if the problem goes away. If that’s the case, then your catalytic converter is clogged. These vehicles have huge problems with the catalytic converters like a clogged during prolonged idle. The military likes to idle their trucks which clogs up catalytic converters. If the converter is dirty, there are many described methods to clean it however, you can always spray it with high intensity, degreaser on the engine side and let it sit, and then blow water through it on the exhaust side.

This truck is an NA and has no catalytic converter, nor is this a problem on NA’s that do…it’s purely a “Turbo” truck issue, at least from my experience

 

[Mogman]

One other thing that you did not cover, have you made sure the return line is not plugged, if the IP wires being switched does not pan out try running a line from the return fitting on the IP into a bucket and then give it a try.

 

[Gary the dog]

The wires are correct on the IP top cover. The exhaust isn’t plugged. I’m thinking it’s something with the return lines too. I removed, cleaned and reinstalled them. I probably should have replaced them. I think there’s too much fuel going to each cylinder which explains the heavy white smoke. Thanks every one for your comments!!

 

[BLK HMMWV]

Leave the check valves out this time

 

[williamh]

Air filter plugged up ? Mushroom cap down to low. ?

 

[BLK HMMWV]

Maybe leave fuel cap off and see if it still stalls.