6CTA fuel shutoff valve stuck open?

[hklvette]

Hi all,

I was wondering if anyone else has seen this issue and found the solution:

Sunday I took the 931 out to an event about 50 miles away. Everything through the day went fine until I got home and tried to shut the truck down. Click the lower switch off, and the engine keeps idling. Thinking that the shutoff solenoid is jammed somehow, I use the emergency stop cable. Still keeps running. I pop the hood open and find that the stop lever is in the "off" position, but its obviously not stopping the fuel flow. To stop the motor, I used a heavy-duty trash bag over the snorkel which worked well. All of the fuel filters were replaced this year, and have very few miles on them. Both fuel tanks are clean, but I did pick up fuel on the way home. The engine does not appear to burn or make any oil, and the idle speed is steady once the engine is warmed up enough to fire evenly.

I did check the stop lever on the IP by hand, and it moves with negligible resistance while the stop solenoid is retracted. Any insight into how the lever works inside the IP would be appreciated.

 

[Jeepsinker]

Is the shutdown lever clamping bolt tight? The lever isn't spinning on the shaft is it?

 

[hklvette]

I did my best to check that but since it was dark outside I'm not 100% sure. Will have to check in daylight this weekend.

 

[hklvette]

So I think I figured this one out. There is a screw on the IP that limits the travel of the stop lever. I think it had worked its way forward, preventing the control rack from moving back enough to stop injection. I actually was able to find an overhaul manual for the MW pump as used on the 466. It was very helpful in diagnosing the problem. You have to be careful to not take too much out of the limiting screw, or the rack can run out of room to move inside the pump.