My B21 will start but when I release the key from the start position it dies. Any suggestions on what the problem might be?
I have a WSM for a B21 I can provide if you use the private message feature of this forum to send me your email address.
By memory, the engine stop solenoid on the fuel injection pump has two independent internal electrical coils. One called the pull in coil which is powerful and the second, called the hold coil which is far less powerful.
In the key switch start position (again from memory) the pull in coil within the engine stop solenoid is powered. When you release the key back to the on position, the hold coil takes over.
If the hold coil or its wiring is damaged or failed, then your engine will not continue to run in the On position.
Check the 5 amp fuse shown as #1 in the wiring diagram
Use a 12 volt test light to check for 12 volt power on the solenoid. Two wires will have power at different times. One as the engine cranks, the other, as the key returns to On from start.
Attach the alligator clip to tbe battery ground and use the sharp end to check each of the circuits on the solenoid. The solenoid has 3 wires, one of which is ground.
Dave