Cummins L10-30 Odd behaviour

[Aviator]

Hi All

I have a 1993 MCI 102-C3 that currently has a 1992Cummins L10-30 mechanical (no ECM) with an Allison Automatic.  The Cummins and the Allison were installed long after the coach was built, because I can see the holes covered up in the floor where the clutch and shifter were and underneath all of the clutch linkages are there.

Anyway on to the oddness.  Engine is running and for no apparent reason it just shuts off, same as if I turned off the master switch.  Oil pressure and water temps are fine. no alarm buzzer.   If I try to immediately re-crank its no start, however it I let is sit a few minutes it will fire right up.  If I have the fast idle switch on the engine will run at fast idle but if its having its issue it will quit if you turn off fast idle.  When its on fast idle and the issue is happening the throttle will do nothing.

I suspect electrical or grounding issues. It seems to me that the electric fuel valve on the injector pump is closing causing the engine to stop. I have an external fast idle governor mounted right beside the engine. It has its own electrical plug out of the same harness the sends a wire to the fuel solenoid.  I haven't traced the wire back to the rear junction box and to the front junction box yet.

Questions

1. Does anyone know where I can obtain a service manual for a Cummins L10-30 mechanical that has some info on the electrical hookups to this engine?  The manual i have only mentions the Electric Fuel solenoid in passing.

2. Could this be a 12V valve?  I suspect so because I pulled a 12V relay while the engine was running and it quit. I'm positive the starter is 24V (verified by meter)

3 I've inspected the engine ground to chassis cable and it goes to two places on the block and appears to be well connected and not corroded. Anything else I should be looking at?

4. Where does the tach feed come from on this engine?

Thanks

Larry

[luvrbus]

There is a manual valve on the solenoid you can use to check for electrical problems screw it all the way in if it keeps running then you have a electrical or solenoid problem,the tach drive is on top of the PT pump 

[Aviator]

There is a manual valve on the solenoid you can use to check for electrical problems screw it all the way in if it keeps running then you have a electrical or solenoid problem,the tach drive is on top of the PT pump 

Thanks  That's the first thing I'll try as soon as i get it to do it again.

Larry