Fuel cut off solenoid problem?

[burnbridge]

I have a Mitsubishi 180D. A couple of weeks ago when I pressed the engine stop button, nothing happened so I stopped it by closing the fuel tap. This happened a couple of times. Now the engine turns over but won't start. Looking at general advice online made be suspect the fuel cut off solenoid. The plunger does not move when the ignition is turned on, or when the engine is turning over, but if I connect the solenoid directly to the battery it moves inwards and stays there, and moves out again when disconnected. Grateful for any suggestions about what the problem is and how to fix.

 

[lens12]

This is a complcating setup as I remember. It is tied into the oil pressure also. I have a service manual that covers it.