How to Replace Fuel Shut Off Solenoid

What Is A Fuel Shut Off Solenoid

The fuel shut off solenoid is a valve controlled by a circuit. Its interior works by pulling a valve with an electromagnet and a return spring. There is no gas tank inside. And its fuel inlet and fuel outlet are inseparable and can be installed interchangeably.

The fuel shut off solenoid is to prevent the oil supply from being cut off after the machine stops. There is no gas storage capacity in the host of the screw machine, the intake or exhaust can be assumed at both ends of the rotor, and the intake or exhaust valves are all peripherals of the host. The intake valve can only be adjusted, and the exhaust valve is simply a check valve that must be replaced if it is not functioning properly.

How Does A Fuel Shut Off Solenoid Work

The working principle of the electromagnetic fuel shut off Solenoid is that the high-pressure fuel generated by the fuel supply pump is distributed to the fuel injectors of each cylinder through the common rail; the fuel pressure is detected by the sensor installed in the common rail, fed back to the control system, and the actual pressure value It is always consistent with the pre-set pressure value adapted to the engine speed and load.

When the plunger goes down, the control valve opens, and the low-pressure fuel flows into the plunger chamber through the control valve; when the plunger goes up, but the control valve is not energized, the control valve is still open, and the inhaled fuel is not pressurized; the fuel flows through the control valve back to the low pressure chamber.

At the same time, the ECU calculates the moment when the necessary fuel supply is met, supplies power to the control valve in a timely manner, and makes it open, cuts off the fuel return channel, and pressurizes the fuel in the plunger chamber.

Therefore, high-pressure fuel is pressed into the common rail through the oil outlet valve; the plunger stroke after the control valve is opened corresponds to the fuel supply; if the opening time of the control valve is changed, the fuel supply will change accordingly, so that the common rail can be controlled pressure.

How to Replace Fuel Shut Off Solenoid

method 1

1. When the power is off and the signal is off, cut off the air source or other power sources.
2. Loosen the thread connecting the electrical and air source interface, and remove the connecting pipe.
3. Remove it from the bracket that fixes the solenoid valve.

When installing a new solenoid valve, install it in the reverse order

Method 2

Step 1: Cut off the air source and remove the damaged solenoid valve with a screwdriver;

Step 2: Install the new solenoid valve with a screwdriver;

Step 3: Insert the electrical control connector into the solenoid valve;

Step 4: Insert the gas line into the quick connector on the solenoid valve;

Step 5: Turn on the power and use the hand-empty switch to debug and check the operation of the cylinder block.

When replacing the solenoid valve, the gearbox needs to be dismantled, and the oil in the gearbox needs to be drained first. The oil dipstick is removed at the bottom of the gearbox. The solenoid valve plays a role in different positions of the control system and is generally replaced every three years.