M939 A2 just stopped

[its me]

Hi all,

looking for some advice. The last time we took the A2 out she started and ran fine then all of a sudden just cut out on us. Now I’m going to have a look at her this week but has anyone any pointers as to what it might be?

she did start back up after a couple of attempts on the starter switch that wasn’t responding. If it’s any help the truck was traveling up hill when it died.

im changing the fuel filters this week.

all the best.
kyle

 

[Coffey1]

Sounds like you had a power failure to fuel solenoid

 

[74M35A2]

Is there fuel in the tank? I love when people post that question, and I’ve been waiting for my turn to do so, but it does have merit.

Did it “feel” like it ran out of fuel (pedal slowly becomes non-responsive), or was it a hard engine cut like God shut the switch off?

If you remove the fuel stop solenoid (10mm bolts), the engine will run with zero electrical power once started. Will even start that way, as long as starter can crank.

 

[Coffey1]

**** good question uphill could be low fuel and fuel pickup came out of fuel.

 

[SETOYOTA]

Always start with the simplest checks. Fuel in the tank is number 1.

 

[its me]

Hey guys,

thanks for the responses. We did indeed have fuel in the tank. It did gradually slow down though.

 

[snowtrac nome]

Sounds like the shut down control, there are 2 coils in them 1 is pull in when cranking and the other is hold. as the hold coil deteriorates over time it will start to let the fuel shutdown lever drop back down. you can wire the shut down lever in the up position to test the theory.

 

[its me]

Sounds like the shut down control, there are 2 coils in them 1 is pull in when cranking and the other is hold. as the hold coil deteriorates over time it will start to let the fuel shutdown lever drop back down. you can wire the shut down lever in the up position to test the theory.

hey thanks for the reply, can I ask where I would find these coils located?

 

[sandcobra164]

Solenoid is on the driver's side of the engine just above the injection pump. Push in on the plunger of the solenoid and zip tie it in the retracted position. You can still shut the engine off with the "emergency stop" cable from the driver's seat.

 

[74M35A2]

The fuel stop solenoid will cut the engine off quickly. If it felt like it ran out of fuel, then it is likely a fuel delivery (suction side) issue. Suspect tank dip tube or failed soft lines on tank suction side to lift pump/filter. One member here suspects the overflow valve in his injection pump was the culprit as well. Cheap and easy to replace. It is the fitting located on the return outline line of the injection pump.

 

[its me]

Hi all,

so a update......turns out I went and spoke to the guy driving it and what happened is. It was sat ideling then when it went to pull away it cut out and was cranking but not starting......so I’m guessing fuel starvation or clogged filters?

what do we all think?

kyle

 

[Coffey1]

1. Take cap off fuel tank with flash light look in tank for fuel there maybe a inch or two in bottom but may not be enough for pickup tube

2. If fuel is there and at least a quarter way up tank check hoses to filter then look at filters for wet places.

3. Push primer see if it get harder as you push it

4 check fuel solenoid .

Just start at tank and follow to injection pump and see where there's no fuel

 

[US6x4]

FWIW...My 813 had 2" of fuel in the tank when I went up a steep hill and the pickup tube pulled in some air. 2" is about 10 gallons in my tank and you definitely need more than that to keep the pickup tube submerged.

 

[Jbulach]

Good advice above... start off cheap, tie the fuel shut off solenoid back, replace 20 gallons of air in the tank with fuel, put the throttle to the floor, crank the starter for a couple 15 second bursts, if it cranks good and don’t fire, start troubleshooting fuel flow from the tank forward.

Were getting better! Shocked so many people have suggested out of fuel, before telling the OP to replace the batteries, and everything on the fuel system, from the tank to the injectors, before even mentioning troubleshooting.

 

[its me]

Thanks for the tips but please excuse my ignorance, how do I tie the fuel solenoid shut?

 

[Floridianson]

replace 20 gallons of air in the tank with fuel,

Nothing wrong with sail boat fuel but it does only work well with a sail boat.

 

[Jbulach]

Thanks for the tips but please excuse my ignorance, how do I tie the fuel solenoid shut?

Any way you can keep it retracted. Heres a zip tie around the fuel line. or as 74m said, take the two bolts out and move it out of the way.

 

[Floridianson]

Sorry wrong thought.

 

[74M35A2]

Yes, add way more fuel to tank (more than 5 gallons). Primer will not work with air in the line unless it can flow. You'll need to crack open one of the bleed screws on the injection pump or hard line fittings going to the filter head, or spin the engine mounted fuel filter loose so it can vent the efforts.

The soft lines from tank may not be wet but still leaking. If you don't know when they have been replaced, then replace them. Just like a tetanus shot at the doctor. They ask when your last one was, and if you say "Ugh....", you have a needle in your arm 4 seconds later.

This is an easy one to find and fix, just need to follow the steps outlined.