【Fault description】
    A Honda Accord car, paroxysmal appearance after the start gradually turn off, start again difficult or unable to start the fault.
    【Inspection process】
    First call the fault code, in the event of failure to check the ignition system, are normal. In the fuel line in the oil pressure gauge, in the pump connection in parallel with a 21W test lamp, the oil pump oil supply and work conditions for simultaneous inspection. Hit the key to "ON" bit, the oil pressure rose to 70KPa, try light, start the engine, work properly. Turn off the key again to play the key to "ON" when the fault occurs, the test light does not shine, no change in oil pressure table. The system static pressure is generally higher than the working pressure, so after the flame to play the key when the oil pressure should rise, suspected failure in the PGM-FI main relay.
    Check the PGM-FI main relay without removing the plug. Connect the light-emitting diode between the positive pole of the battery and the 8th pin. After the key is turned on several times, the fault occurs, the light-emitting diode is bright, the test lamp and the oil pressure gauge are not changed , Identified as PGM-FI main relay failure. After the replacement of several tests, the fault disappears.
    【Fault Analysis】
    The PGM-FI main relay consists of ECM main relay and oil pump relay. When the key is activated to the "ON" position, the ECM main relay is energized for powering the computer, injector and pump relay. The computer receives the ECM main relay output signal, the oil pump relay 8 feet to send 2s ground signal, so that the pump relay suction 2s, for the fuel system pressure. In the 8th foot and the battery directly connected to a light-emitting diode, is to check the ECM main relay and the computer is working properly, the pump relay is triggered signal.
   
    【Maintenance】
    When the pump relay fails, the residual pressure in the system allows the engine to start, but with the oil pressure decreases, the engine gradually turn off. As the pump relay work is unstable, then restart the oil or not oil, so that the engine appears to restart difficult or can not start the fault.