M931A2. Fuel prime

Well i had a fine running truck until I changed the fuel filters. No issues other than it would start on the second hit of the starter.

So I decided to change my fuel filters. The large canister filter was full of crud. Red smells like paint. Algae maybe ?

changed the spin on small filter.

I filled the canister and spin on with diesel before installing each.

Hit the starter and she fired right up. I was letting the truck idle while I picked up my tools and she died. Ran less than five minutes.


Now it won't start just spins.

the tm appears to show the priming for only the a1 series. I assume i just push the button thats there. Is there a valve I need to open to see if fuel is coming through?


this is one of those rebuilt units with 700 miles.

Any ideas here on my next step. The truck is a recent GL purchase. Drove home about 30 miles and it ran great.

When I ran mine out of fuel once I had the same problem. I found if you pumped the primer a bunch of times (20-30) then unscrewed the small secondary fuel filter it would release a bunch of air. I did that a few times till I had no more air and just fuel coming out of secondary filter. Tighten filter give it a few more pumps and she ran great.

That's ALOT of extra work, and effort.

The "correct" and easiest by the way method to properly bleed the A2 is just as it is in the TM. Go up to the front inboard side of the Injector Pump. You will see a small nut with a screw in the middle. Loosen that a little (its the vent) pump the snot out of the priming pump on the side of the engine. When you get NOTHING but fuel, not just the start of getting fuel, stop pumping, close the vent and start the truck. Start to finish, should be about 45 - 60 seconds.

I have trusted the fuel gauge now twice when I shouldn't have, and this solution worked perfectly both times.

I will look for that. Both TMs I have cover both the A1and A2 but for priming it only shows the old 250 in the figures least that's all I could find.

Which TMs do you have?

From the TM...

doghead said:

Which TMs do you have?

From the TM...

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Yes, Number 6 is the correct vent. In the TM picture, its not clear that it is located inboard and forward on the pump. Once you find it, its easy.

I kind'of have the same problem, I drained the water separator ( about 1-2 quarts) and then tried to bleed the air out of the system with the primer pump as in the TM's and nothing happened. I pumped that thing for about 2 full minutes and no fuel or air. I think there might be a seal in there that is shot. If I spray some oil on it should that do the trick or should I just get a new primer?

I think they are from this site. In the section for priming the figure (6 I think ). Only shows the 250. Maybe I didn't get all the pages. Thank you for posting.

The "correct" and easiest by the way method to properly bleed the A2 is just as it is in the TM. Go up to the front inboard side of the Injector Pump. You will see a small nut with a screw in the middle. Loosen that a little (its the vent) pump the snot out of the priming pump on the side of the engine. When you get NOTHING but fuel, not just the start of getting fuel, stop pumping, close the vent and start the truck. Start to finish, should be about 45 - 60 seconds.

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What he said. I almost went blind trying the start that ^&(&&$*E wrecker until Wheelspinner PM'd me the skinny. No issues now getting one primed or cranked if there is fuel in the tank and the primer pump isn't sucking air.

One other issue. May be the fuel shut off. I took a peep this morning before work to find the bleeder valve. I noticed the shut off in what I think the off position. Flipped the battery switch and it did not move. I thought it would/ open when the battery switch was turned on. Is that right?

Not quite. The power switch and the "ignition" switch need to be on. But I have found that if your batteries are a little low (even just a very little) the solenoid will not pull in. Here is what I do when this happens. Turn on both switches. Then grab the fuel shutoff lever and turn it to the run position (counterclockwise), forcing the solenoid plunger up into the solenoid at the same time. Once it is pushed in, it will stay with the battery power supplied. Then return to the cab and crank the truck. If the solenoid plunger does not stay pulled in when you help it, you have a different problem, like a bad solenoid or no power to it.

I plan to check out the solenoid tomorrow. Maybe that will be it. This morning I did have a chance to go back to the truck. Flipped the battery switch on an the starter switch to run. The fuel shut off was still in the closed position.

I don't think the shut-off solenoid will pull back to the run position until the engine is actually cranked (?). I have run my truck out of fuel several times, the most recent being yesterday, because I suck. I used to be able to blame it on a non-functioning fuel gauge, which now works. Yesterday, I thought it could run forever on "E" like a car, but I was taught differently.

Everything folks are saying is correct. Cracking the bleed screw on the inboard side of the injection pump toward the front, is the best place. Pump engine mechanical pump plunger until absolutely no air bubbles come out of the screw, then tighten it, pump a few more times, and you should hear/feel the fuel flowing through the injection pump as the pressure relief valve opens inside the injection pump (banjo fitting on the outlet hose of the injection pump). Get in, hold the pedal to the floor and crank. The engine should start and run. Will be rough at first.


It is kind of difficult to see if the stop solenoid is pulling back as a one man operation from the cab, and I have had mine act funky and not retract during cranking when run out of fuel for some reason. In those cases, I carry zip-ties and simply pull the plunger back and zip tie it in this run position to get the engine running after run out of fuel. I should probably just replace my stop solenoid.


After doing it so many times, I probably hold the low time record on getting a 6CTA8.3 re-lit after running out of fuel. I really should just keep more fuel in the truck.

If you have red yummy stuff in your fuel, yes that is likely algae, which is also a sign of water in your tank. You should pull the drain plug, empty it, and put some diesel biocide in there. Run for a tank, then change both filters again. That should take care of algae anyway.

I recently had the same problem. I pressurized my fuel tank with a compressor hose and pressurized the system. I started the truck after that with no problem. I also cracked the injector pump to bleed out any air just to be safe. I haven't had any problems after that.

The solenoid was not functioning. I tied off with zip ties. Still would not start. Bled the injection pump per tm and instructions here. It fired right up after that. Let run for maybe 15 minutes at 1000 rpm. Brought it Down to idle and took it for a drive. All seems well at this point. Hopefully it will start tomorrow after sitting.

now the solenoid appears to be functioning.

Where do you get diesel biocide? Aut zone? Type place

SETOYOTA said:

Where do you get diesel biocide? Aut zone? Type place

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A marine store, as in boat, should have the algaecide.

Bosch inline pumps will self prime. Hold your foot to the floor and crank it, it will start.
The FSOV has two circuits, pull and hold in. Pull in happens when the engine is cranked, the plunger will pull in. after the engine starts, the hold in voltage takes over and keeps the sol. energized until the power is shut off, the ign swithc, not the power.

Where do you get diesel biocide? Aut zone? Type place

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Never had any luck finding it local. I order mine from Amazon: http://www.amazon.com/Hammonds-Biob...ie=UTF8&qid=1412393291&sr=1-1&keywords=biobor

My local NAPA has the anti-algae on the shelf, called Bio-Kleen, made Power Service, in a white bottle shelved with other diesel fuel treatments. A different local auto parts store may have it also.

My shut-off solenoid acts the exact same way. Doesn't work when run out of fuel, but seemingly ok when normal starting/running. I think excessive cranking energizes the more powerful pull coil in the solenoid for too long and overheats it.

The bleeder cap/screw/bolt on the 8.3 is 10mm. Good idea to have a 10mm box wrench onboard just in case.

70deuce said:

The bleeder cap/screw/bolt on the 8.3 is 10mm. Good idea to have a 10mm box wrench onboard just in case.

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Good advice