Fuel injectors inject fuel into the engine cylinders based on signals from the ECM. The amount of fuel supplied depends on the injector opening time, i.e. on the width of the voltage pulse supplied to the injector winding.
Checking with a stethoscope
1. With the engine idling, use a stethoscope to check the operation of the injectors for clicks. As the crankshaft speed increases, the clicks should become more frequent.
Note: Ensure that clicking noise from an adjacent injector is not transmitted through the line to the inoperative injector.
2. If you don't have a stethoscope, use your finger to check the operation of the injectors for clicks. If there are no clicks, check the reliability of the connectors to the injectors and the output voltage of the control unit.
Resistance: 15.9±0.35 Ohm at 20°C
2. Connect the connector to the fuel injector.