How does a shut off solenoid work?

Solenoid fuel shut off valves are used to close the main jet or main fuel circuit in the carburetor when the key is turned off. The solenoid valve works by using a spring loaded plunger to press against the main fuel circuit passage and prevent fuel from entering the passage.

How does the fuel shut down solenoid work?

I thought I would start this thread regarding testing these components when troubleshooting. The fuel shut down solenoid turns the fuel on and off. It contains 2 coils which are powered separately; the pull coil and the hold coil. The pull coil is energized thru the fuel shut down relay.

How is the solenoid connected to the relay?

When you turn you key to start, the starter solenoid wire is energized and also the pin on the passenger side of the relay. Electrical power then goes thru the relay coil to ground thru the pin on the drivers side. This activates the relay.

Where is the fuel shut down relay located?

The pull coil is energized thru the fuel shut down relay. The hold coil is energized, by a separate circuit, thru fuse #9 in the fuse box by the drivers door. In order to show the pins, I had to take the picture using a mirror so the pin numbers appear in reverse.

When to disconnect the jumper from the solenoid?

Disconnect the jumper on battery negative. The spring should return the solenoid to the fuel off position. If the solenoid passes this test the solenoid is good. Note high amperage is generated when using the jumper on the white pin.

How does a shut off solenoid work?