M931A2 won't start

[Scott88M]

Lol. Like I always say: even a stopped clock is right twice a day.

 

[jwesley74]

Need some help on 925a2. Truck had bad algae problem in tank from auction. Drove it 1000 miles and finally able to drain/clean tank. Primer pump check valve had debris/algae in it. And primer hand pump started leaking after taking apart & cleaning screen and check valve. So ordered new primer pump. Finally got to install new pump last night, pressurized tank, bled air out and started up. It idled for 20-30 minutes then would die. Lost prime. So prime it again. Repeated process 6-7 times. Gave up last night. Today, bled again, pressurized tank found small drip from elbow supply line into primer pump. Took elbow out, wrapped with teflon tape and no drips now. Bled system, starts up and runs. Now the puzzling problem. When engaged in gear it stalls. Cannot keep it running when engaged in gear. Even with rpm's up to 1000 and engaging it stalls. It sounds like its still starving for fuel and/or air still in line. My buddy gave up for now, I'm working but will try to figure out when I get home this afternoon. 1st I'm going make certain supply lines are bled of air. If problem still persists I want to pull return line and inspect/clean check valve and verify its pumping fuel thru and no air in line on return side. Any other suggestions are appreciated.

 

[Suprman]

Did you replace both fuel filters and back flush the entire system to get all that crap out of there. The last thing you want is a gunked up injector pump.

 

[jwesley74]

Yes, changed both filters before I drove it 1000 miles, changed halfway thru trip & installed new filters yesterday after cleaning tank and lines. Put all new diesel in it along with Algae X. So 1st time it started after cleaning system, installing new primer pump, new filters and fresh diesel was last nite.

 

[Suprman]

You can unscrew the fill screen from the tank and peek in there make sure the pickup tube isn't gunked. I have heard of pickup tubes loosening and having issues. Fuel problems can be a pain to diagnose.

 

[porkysplace]

Yes, changed both filters before I drove it 1000 miles, changed halfway thru trip & installed new filters yesterday after cleaning tank and lines. Put all new diesel in it along with Algae X. So 1st time it started after cleaning system, installing new primer pump, new filters and fresh diesel was last nite.

You would be better off posting these questions in your thread you have going on your algae problem so people know what you have already done and keep from derailing this thread .
M925A2 Fuel Tank Algae?? Black tar

 

[EMD567]

Yes, operator error. I was not aware of the fuel tank switch on the floor. I've driven dual tank trucks before that had a single switch on the dash. I was expecting that switch to change tanks and fuel sending units. The batteries are charging now, I've filled both tanks. I'll prime it and try it tomorrow evening. Thanks for all who tried to help. I've read the 10 TM, but clearly not cover to cover. Sorry to those who feel their time was wasted.

Mikey

I wouldn't worry. You weren't the first to forget the valve on the floor, and you won't be the last.

I chased air leaks on my fuel system for weeks. My friend and hero told me to change the flexible line from the filter to the IP. I refused, thinking that it would be wet if it was letting air into the fuel system. Finally broke down, replaced the line, and the engine runs like nobodies business.

He hasn't let me forget either.

 

[Retiredwarhorses]

Been reading through all these posts...OP, you do know the fuel tank selector is on the left side of the truck on the floor at the bottom of the seat right? The tank selector on the dash ONLY tells you the amount of fuel in each tank...so selecting the dash switch does not change tanks....

 

[Retiredwarhorses]

Lol...never mind....just Reqd the above posts....I got through 5 pages before posting possible issue.