This has the cummins nhc 250- 855 ci 14liter small cam cummins engine, uses a pt injection pump, no in tank pump, no lift pump, its just fuel line from tank to fuel filter and then to the pump, they are a pain in ass if have a tiny leak, and the filters that came on them were known for leaking, i have the same engine in my 1983 m925 5 ton cargo truck.i pulled the stock filter off and put napa 4770 screw on filter, and now it starts up everytime no issues, ken spencer of MV parts sells a double filter kit with lines, swap out and you wont regret it. Some people do put lift pumps on but if dont have any air leaks really no point. Glad to see you got it running, those motors are brute and last for ever, they had them in many older trucks, tractor trailer.
Having a similar problem with my M813, the pump's fine, it will run but not for long. I'm sucking air into the system somewhere. Swapped the old filter assembly with a Wix filter and fuel separator and put new hoses in. After it stalls out the filter is half full of fuel. Next step is to check the pick up pipe by bypassing the fuel tank.
I rebuilt those cummins motors in army,changed hundreds with my 5 ton 816, the fuel pumps on those are super touchy sometimes. I made a gas cap for fuel tank to pressurize with air hose. Solves start up issue. The little spring in the pump actually gets week over time. I recommend installing a 2nd fuel filter in line with . Injectors ive only seen issues with tips broken or burned off. They run forever.
@@wrmexcavator3309 easy trick to install sleeves get block warm put sleeves in freezer or cooler be fast they slide right in. I was at ft polk Louisiana in early summer hot wasnt word for it. Had own dino in building did multiful motors also I turn them up easy way advance your pump timing so it is just before tdc in pump sight window
The m35 series trucks had a lift pump, but not sure why they didn't put them on the 800 series trucks like yours. Do you have a part # for the spin-on filter housing? Thanks!
This has the cummins nhc 250- 855 ci 14liter small cam cummins engine, uses a pt injection pump, no in tank pump, no lift pump, its just fuel line from tank to fuel filter and then to the pump, they are a pain in ass if have a tiny leak, and the filters that came on them were known for leaking, i have the same engine in my 1983 m925 5 ton cargo truck.i pulled the stock filter off and put napa 4770 screw on filter, and now it starts up everytime no issues, ken spencer of MV parts sells a double filter kit with lines, swap out and you wont regret it. Some people do put lift pumps on but if dont have any air leaks really no point. Glad to see you got it running, those motors are brute and last for ever, they had them in many older trucks, tractor trailer.
Having a similar problem with my M813, the pump's fine, it will run but not for long. I'm sucking air into the system somewhere. Swapped the old filter assembly with a Wix filter and fuel separator and put new hoses in. After it stalls out the filter is half full of fuel. Next step is to check the pick up pipe by bypassing the fuel tank.
I rebuilt those cummins motors in army,changed hundreds with my 5 ton 816, the fuel pumps on those are super touchy sometimes. I made a gas cap for fuel tank to pressurize with air hose. Solves start up issue. The little spring in the pump actually gets week over time. I recommend installing a 2nd fuel filter in line with . Injectors ive only seen issues with tips broken or burned off. They run forever.
Thanks for the info. We are getting close to a rebuild on it.
@@wrmexcavator3309 easy trick to install sleeves get block warm put sleeves in freezer or cooler be fast they slide right in. I was at ft polk Louisiana in early summer hot wasnt word for it. Had own dino in building did multiful motors also I turn them up easy way advance your pump timing so it is just before tdc in pump sight window
OUTSTANDING!!!!! AIRBORNE!!!!!
Ole Chris knows what he's doing 👍
Don’t tell him that 😉
Going over the dirt pile was impressive. My international won’t quite do that.
My kenworths won’t either lol
Pick up tube in the tank probably has pinholes in it
Thanks
That's what mine ended up being. Somehow a steel pickup tube had been installed and rotted out.
The m35 series trucks had a lift pump, but not sure why they didn't put them on the 800 series trucks like yours. Do you have a part # for the spin-on filter housing? Thanks!
I’ll look tomorrow for you. Thanks for watching