Fuel system fault diagnosis analysis
a. Air leakage in low-pressure oil line
(1). Oil pump inlet pipe;
(2) Diesel filter (the diesel engine power is insufficient, the filter element should be checked and cleaned first);
(3) Diesel filter oil inlet pipe;
(4) Hand oil pump (most problems occur here);
(5) Fuel tank vent (for air exhaust, check if it is blocked);
(6) Fuel tank (the fuel tank suction pipe is welded to the tank, and cracks or pinholes in the weld will cause air to leak into the fuel system, which is often overlooked)
b. Speed regulator failure
c. Smoke limiter failure
The smoke limiter located on the smoke limiter uses the air pressure in the intake pipe to adjust the air-fuel ratio to achieve the purpose of controlling smoke. Damage to the smoke limiter will result in insufficient power and increased smoke exhaust. If the air pipe from the intake pipe to the smoke limiter is leaking or blocked, it will also cause power reduction and increased smoke exhaust.
If the vacuum tube on the smoke limiter breaks, the power of the diesel engine will decrease.
d. The diesel engine low idle speed adjustment screw can be adjusted
e. To determine whether a cylinder is not working, the cylinder disconnection method can be used to check. After determining which cylinder, remove the faulty injector for debugging, and check whether the injector is equipped with an extra sealing copper gasket. At the same time, check whether the fuel injector is faulty, and you can connect it to the outside of the engine for testing.
f. Oil return (you can check the oil return amount of the diesel engine at rated speed to determine whether there is a problem with the oil circuit)
