The engine shuddered

[tom lovinggood]

Hello--1986 M1009-runs very well--new IP installed about a year ago. Took it out for a drive today, and went for about 60 highway miles, with no problems. Stopped at a red light, and the engine shuddered briefly, then shut down and would not re-start. Had plenty of fuel, and the starter turned over with no problem. Had the vehicle towed back to my house, where l am considering options. Anyone have any thoughts? Thanks in advance.
Tom Lovinggood

 

[NDT]

Maybe the lift pump failed. Maybe an electrical connector in the ignition circuit failed. Maybe the fuel pickup in the tank is plugged. Usually I suspect the injection pump but it’s safe to eliminate that at this point.

 

[Keith_J]

Lift pump isn't critical, transfer pump in the IP can draw 18 inches of mercury. Crack the filter air release valve on top of filter while cranking to test.

Easiest test of the most likely culprit would be the ETR solenoid in the IP. Key on, disconnect the pink wire at the IP and listen for a click. Look for a spark too. If you hear a click, then try this with the throttle held open, this time feeling for a tap on the throttle lever as the pink wire is connected.

If the ETR solenoid tests pass, the next test is for a plugged fuel return. Reconnect the pink wire and disconnect the green wire. Jumper this terminal to 12 volt positive and try starting. This should also make a click. Then try starting. Debris can plug the fuel return, this terminal gets 12 volts on cold start, reducing case pressure for better starting. Engaging when hot can clear any plugs and also advances timing.

Finally, disconnect the fuel return fitting and crank the engine, looking for fuel flow. Finally, check for gasoline in the diesel.

 

[tom lovinggood]

Got lucky once again. Had my M1009 towed to a local diesel shop after the motor died last week. Turns out that there was only air in the fuel line and once it was bled out, she started right up. Thanks to all that offered their opinions.
Tom Lovinggood

 

[cucvrus]

Got lucky once again. Had my M1009 towed to a local diesel shop after the motor died last week. Turns out that there was only air in the fuel line and once it was bled out, she started right up. Thanks to all that offered their opinions.
Tom Lovinggood

This may not be the end of this issue. How did air get in the line to begin with? If it sucked air once and all they did was bleed the air, I would be concerned as to how the air got there in the first place. Unless you are not telling the part of where they discovered the air leak and fixed it. Keep your eyes open for issues. And don't stray too far from home with that truck till the issue of fuel drop is corrected. Have a Great Weekend.

 

[tom lovinggood]

Thanks to all that answered my query--it appears that the fuel level in the tank got low and when I was going up a hill, air got sucked into the injectors. I apparently let the fuel level get too low to allow this to happen. As I had mentioned, the fuel gauge only works intermittently. I am in the process of getting that fixed. Everything appears to be working well now, and my M1009 in back on the road. T hanks again to all that offered their help.