HMMWV Fuel Issue

[corbinenoble]

Was hoping to possibly get a bit of insight from anyone who has possibly dealt with the same issue before and knows these trucks well enough to point me in the right direction. I’m pretty mechanically inclined but am new to the HMMWV. I currently own a 2009 M1123 which has been a great reliable truck until recent. Ive recently had an issue starting the truck after it has sat for a week. The truck will start up strong and run for roughly 5 seconds before the engine revs up for about a second or two then dies. I then have to crank the truck over for roughly 10 seconds before it’ll start again and run without issue. I could be way off but this seems like a fuel delivery issue and am just curious if anyone else has had a similar problem. I appreciate any help!

 

[Maxjeep1]

My M1123 was perfect and then it suddenly developed a condition when I gave it any pedal on cold start it would die. I ran some Diesel Kleen in maximum strength and it was amazing after a few hours

 

[TNDRIVER]

Was hoping to possibly get a bit of insight from anyone who has possibly dealt with the same issue before and knows these trucks well enough to point me in the right direction. I’m pretty mechanically inclined but am new to the HMMWV. I currently own a 2009 M1123 which has been a great reliable truck until recent. Ive recently had an issue starting the truck after it has sat for a week. The truck will start up strong and run for roughly 5 seconds before the engine revs up for about a second or two then dies. I then have to crank the truck over for roughly 10 seconds before it’ll start again and run without issue. I could be way off but this seems like a fuel delivery issue and am just curious if anyone else has had a similar problem. I appreciate any help!

Have you removed the fuel filter housing from the firewall, cleaned and replaced the filter and water separator????

 

[Mogman]

The check valve in the return fitting on top of the IP has some trash in it allowing the fuel to drain back to the tank while sitting for a long time.
Remove the rubber return line, then the fitting and inspect for trash, make sure no trash gets into the IP, it should have a glass ball in it so light should shine through
OR you have a leak in one of the rubber lines.