M998 6.2na help: engine quits, won’t restart right away

[Ger_e31]

M998 6.2. Engine starts fine. Runs for 10-15min. Then sputters, and dies. Try to restart-light flashes, no clicks of the inj pump solenoid, no start. Let it cool down, get the proper clicks, wait light, etc, and starts-dies shortly thereafter…repeating the process. Come back next day, same cadence.

1) fuel lines, filter, pump, return lines all good. Fuel is good.

2) changed inj pump solenoid, problem remains.

3) putting blackdog grounding straps on this evening and trying again.

what else can it be? Thanks

 

[Al Capone]

Sounds like smart box doing weird stuff . Are your batteries both good ?

 

[Ger_e31]

Batteries good.

with Harness removed from temp sensor/glow plug controller….should I be able to start the vehicle? I removed harness from sensor, turned eng to run….proper wait light indications, and engine started. I thought it should just blink when I did that.

 

[Coug]

Stop just throwing parts.
Verify whether you have 24V at the solenoid when hot. If you do it may be a fuel system issue, if not it's electrical.


At that point if it's electrical it may be a failure inside the start box.



I'm not as up to speed on them, but if nothing else you can pull it out and open it up (make sure you disconnect batteries first) and start looking for components that look toasty/fried.



When the engine shuts off do you still have all the other electrical inside the truck working (blower motor, lights?)

 

[Al Capone]

Another question - do you have the military on / off switch still or has someone puts Chinese key switch in it ? I ran key switch for while but swapped back to original switch and puta fuel shutoff locked switch inline . I had had smart box issues and had to replace so at that point I went back to original switch . Not saying this caused it but heard people saying they cause issues . As coug said check for power at fuel shut off when it gets hot . When I first got my truck I had starter solenoid stick engaged . (It’s inside smart box ) I had thought it was on top the starter . Nope . It sucks to remove a starter by the way . I kicked the smart box and it fixed it lol . That box lasted for about 3-4 years . It finally went out after leaving truck outside in rain storms for few days . It started doing all the weird stuff . Like flashing light . No flow plugs working . I changed box and temp sensor and was all good to go . Opened up the box I removed and it had water in it . I recommend sealing up any holes in the body panel above it and mainly the 4 mounting bolts .

 

[Ger_e31]

all original switches-no keyed switches.

found the glow plug controller/tsu damaged. Wiggling it, and the electronics inside were easily exposed. Ordered the correct part that matches the control box. As soon as that gets installed, will run the engine again and test for voltage if it fails.
Per the diagram on page 12-4 fig 12-3 on the hmmwv component testing and troubleshooting guide…the glow plug controller connects to 54a going to the fuel solenoid. Am not a schematic reading person….does this mean it is drawing power from that 54a line, or is it controlling the flow of electricity to the fuel solenoid.
Thank you again to all for the help

 

[Ger_e31]

Control box is SSI TECH 12469159-1
Glow plug controller is KDS 12469159-2

 

[Al Capone]

Without looking and following wiring diagram I can’t answer that question .

 

[Milcommoguy]

Control box is SSI TECH 12469159-1
Glow plug controller is KDS 12469159-2

SSI is old OLD school.

Old truck too, CAMO