The fuel injector nozzle itself is a normally closed valve (normally closed valve means that the valve is always closed when no control signal is input; and normally open valve is when the control signal is not input, the valve is always open), by a valve The needle moves up and down to control the opening and closing of the valve. Next, the editor will explain what are the reasons for the failure of fuel injector nozzle, and what are the performances of the injector failure.
What are the reasons for the failure of fuel injector nozzle
1. The relay is damaged.
2. The fuel injection nozzle is blocked and cannot work.
3. The fuel injector nozzle harness is short-circuited due to aging.
4. Loose connection of fuel injector nozzle harness leads to poor contact.
Structure of fuel injector nozzle
The gasoline fuel injector nozzle used in the EFI engine is electromagnetic. The fuel injection nozzle is installed on the engine intake manifold or cylinder head near the intake passage through an insulating gasket, and its position is fixed with a pressure oil delivery pipe. After receiving the fuel injection signal, the electromagnetic coil of the fuel injection nozzle is turned on. Under the action of the magnetic field of the electromagnetic coil, the plunger rises against the spring force, and the needle valve clutch seat is brought up to remove the pressure gasoline from the fuel injection port. ejection. According to its structure, the fuel injection nozzle can be divided into needle valve type and ball valve type. It is easy to block under the injection port of the needle valve type injection nozzle, and the gasoline sprayed from the injection port of the ball valve type injection nozzle is atomized well. According to the resistance value of the electromagnetic coil, the fuel injection nozzle can be divided into two types: low resistance value and high resistance value. The resistance value of the low resistance nozzle is about 2-3Ω, and the resistance value of the high resistance nozzle is about 13-16Ω. The shape of the electric plug of the fuel injection nozzle is often used to indicate the type of the fuel injection nozzle and the size of the resistance value.
What is the performance of the fuel injector nozzle failure
1. Clogged spray holes
It can be cleared with a needle, and it must be cleaned carefully after clearing. The large plane of the needle valve body is not in good contact with the plane of the injector body, or the cylindrical surface of the needle valve is worn out. If the large plane of the needle valve body is not in good contact with the plane of the main body of the fuel injection nozzle, chromium oxide can be applied to the flat plate for "8" shape grinding; if the cylindrical surface of the needle valve is worn more, the needle valve couple should be replaced in pairs.
2. Poor sealing
Poor sealing of the needle valve and the needle valve body, resulting in poor atomization or dripping of the fuel injection nozzle.
This kind of fault can be coated with fine chromium oxide or toothpaste on the sealing tape of the needle valve end, but do not apply to the cylindrical part, and then insert the needle valve into the needle valve body, knocking and turning until it is tight. After grinding, the chromium oxide or toothpaste must be washed away.
3. There is air
There is air in the oil circuit. Just remove the air from the oil circuit.
4. Poor oil supply
The oil pump needs to be repaired. If there is a leak in the oil pipe joint, try to connect it so that it does not leak.
5. Insufficient elasticity
The spring force of the piston spring is insufficient or the spring is broken. The spring should be replaced.
6. Piston wear
Piston wear affects oil supply. The piston needs to be replaced.