M923-A2 wont start. done everything

[goldneagle]

Had a starting issue on my M936 wrecker. Replaced the fuel filter with spin on and new fuel line to IP. NAPA sells a universal hose that is almost as stiff as hydraulic hose but made for the push-on fittings. I reused my fittings with the new hose. Worked on first attempt.

Here are links to filter base and spin-on filter:

http://smile.amazon.com/gp/product/B000CSGT64/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 was $28

http://smile.amazon.com/gp/product/B000CSIOEO/ref=oh_aui_detailpage_o01_s02?ie=UTF8&psc=1 was $20

 

[Alexsha]

Copper

Ugh. I sure as **** hope I don't have a split/crack in those.

 

[Alexsha]

Had a starting issue on my M936 wrecker. Replaced the fuel filter with spin on and new fuel line to IP. NAPA sells a universal hose that is almost as stiff as hydraulic hose but made for the push-on fittings. I reused my fittings with the new hose. Worked on first attempt.

Here are links to filter base and spin-on filter:

http://smile.amazon.com/gp/product/B000CSGT64/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 was $28

http://smile.amazon.com/gp/product/B000CSIOEO/ref=oh_aui_detailpage_o01_s02?ie=UTF8&psc=1 was $20

Is that filter base the same or similar to the Fleetguard 3302367S? Did it bolt right into the old mounting holes or did you have to modify anything?

 

[buggin]

Ok
i hooked up a sprayer bottle full of diesel to the fuel line at the primer(to bypass tank and lines). When the tank is pressurized it starts and runs. If I release the pressure from the tank, it runs for a few seconds(20ish) then dies. If I don't put pressure in the bottle I can't hear the primer spraying fuel into the injector. It won't start unless I pressurize the tank. Diagnosis?

 

[helomech]

Sounds like a leak in a fuel line.

 

[Warthog]

He bypassed all the fuel lines and connected the can of fuel directly to the IP. Only runs when the fuel is pressurized.

I an not familiar with the 8.3L IP. Maybe someone will chime in shortly

Good catch on the testing.

 

[helomech]

Got you. I misunderstood. Sounds like a bad pump then.

 

[74M35A2]

When you say you hooked it up to the primer, does that mean before or after the mechanical lift pump (since the primer button is part of the lift pump).

Regardless, your problem is either the lift pump, fuel filter/housing, suction line, or dip tube within the tank. Next, run a hose from the suction side of the lift pump into a can of diesel and see if it will prime/run. You will have to open the bleed valve on the IP to do this correctly. If it runs OK, then keep doing the same thing, but work backwards toward the tank. Do same experiment but have the fuel filter in series next. If it runs OK, then pull out the fuel tank dip tube, check it for cracks, and also the connection at the top of it. I wouldn't even test the fuel suction line, so many problems on here with them, just replace it.

I did buy an 8.3L mechanical lift pump brand new on eBay for super cheap, if you need one (look there).

 

[buggin]

Got it. Thank you for all the help. The lift pump was bad. Pulled one off of the parts truck. Runs great.

 

[Warthog]

Thanks for the follow up. Glad you got it running.