Fault phenomenon
    A Honda Accord 2.3L displacement of the car engine, high-speed operation is basically normal. Once into the idle state, there will be unstable operation, shaking, shock and other phenomena.
    Fault check and analysis
    This engine uses the PGM-F1 gasoline injection system. First in accordance with the routine inspection of the car's oil and circuit work. After inspection, the gasoline jet system lines, piping, oil and fuel injectors are normal, the transistor electronic system is no abnormal phenomenon. Finally, when the engine water temperature sensor is checked, the resistance value is too small. Thus, a sliding resistor is inserted into the water temperature sensor circuit in the machine for detection. When the resistance value reaches a certain resistance, the engine idling operation tends to normal. This indicates that the fault is due to the temperature sensor being too small.
    PGM-Fl is a change in the resistance value of the thermistor to detect the variation of the cooling water temperature and to change the change in the resistance value into the control unit. Using the voltage signal, the basic injection time is also corrected according to the cooling water temperature. The resistance of the water temperature sensor is shown in Table 1. It can be seen from the table, the cooling water temperature is low, the thermistor resistance is greater $ cooling water temperature is high, the thermistor resistance is small.