What should I do if I turn off the engine without stepping on the accelerator? Why can I only start by stepping on the accelerator?

The typical fault that a vehicle can be started only by stepping on the accelerator is that the battery voltage and starter work normally, but the engine cannot be started, so it is difficult to start or cold start. There are corresponding fault reasons such as accelerator, idle switch, water temperature sensor and temperature sensor. In addition, the quality of fuel used in cars is poor, and the combustion effect in engines is not very good.

The fault of the accelerator can be measured from the voltage between pin 5 and pin 7 of the accelerator control part (stepping on the accelerator pedal or pulling the rope), which should be between 0.4 and 4.5V under normal circumstances; If the voltage is abnormal, repair and replace the throttle potentiometer, repair related lines, and adjust the installation position of the throttle pull rope.

Idle switch mainly checks the resistance values at both ends of the switch. When stepping on the accelerator pedal or pulling the rope, the resistance value should be displayed. On the contrary, when the resistance value of the accelerator pedal or the pull rope should be less than 1? ; If the corresponding resistance does not meet the normal range, repair or replace the idle switch and other related circuits.

The resistance values of water temperature sensor and air temperature sensor both change with the change of temperature, and the interval should not exceed 2℃, and decrease with the increase of temperature (NTC); If the water temperature is abnormal, check or replace the sensor and related circuits.

It should be noted that long-term use of inferior fuel will lead to premature aging of internal spark plugs, and the gap between spark plugs will become larger, thus causing damage to fuel nozzles. In severe cases, the engine will not leave the cylinder, resulting in idling flameout.