Yuchai Guo Si EFI, the engine is not as big as before, and the fuel consumption is a little higher. What is the reason?

(1) The air filter is blocked, resulting in poor air intake, rich mixture or blocked exhaust pipe.

(2) The idle speed adjustment is incorrect. E.g. CO adjustment error.

(3) The engine coolant temperature is too high or too low. If the coolant temperature is too high, the coolant will easily boil, the power will decrease and the fuel consumption will increase; The coolant temperature is too low, the mixture is not atomized well, the engine power decreases and the fuel consumption increases.

(4) the ignition timing is not allowed, such as ignition is too late.

(5) The cylinder pressure is too low. Practice has proved that the cylinder pressure is lower than the specified value, and the fuel consumption increases by 20% ~ 25%.

(6) The gas distribution phase is incorrect.

(7) The exhaust gas recirculation valve is stuck and normally open.

(8) Use summer lubricating oil or excessive oil filling in winter.

(9) Internal damage or serious wear of the fuel injector.

The engine is badly worn. For example, the cylinder leaks.

(B) the reasons for electronic control

(1) The coolant temperature sensor is faulty. If the working characteristics of the sensor change, the fuel injection correction signal will be inaccurate.

(2) The intake pressure sensor is faulty. If the output pressure of the sensor is too high, the mixture will be too rich.

(3) The air temperature sensor is faulty.

(4) The oxygen sensor is faulty. If the sensor is short-circuited and the sensor voltage is 0, the computer receives the signal of lean mixture and instructs to increase the fuel injection quantity.

(5) The throttle position sensor is faulty. If the throttle position signal is wrong.

(6) The air flowmeter is faulty.

(7) The oil pressure regulator is faulty.

(8)ECU and connector are faulty.

(9) Deflagration sensor failure.

(10) The activated carbon tank is faulty.