INJECTOR CHECK


CHECK THE OPERATION SOUND

1.Use a stethoscope to listen to the operation sound (clicking) of the injectors while the engine is idling or cranking.
caution Beware that the operation sounds of other injectors can be heard even if the injector that is being inspected might not be operating.
2.Verify that the operation sound increases with the engine speed.
note If the operating sound cannot be heard, inspect the injector actuation circuit.

MEASUREMENT OF RESISTANCE BETWEEN TERMINALS
1.Disconnect the injector connector.
2.Measure the resistance between terminals.
Standard value: 10.5 - 13.5 Ω (at 20°C)
3.Connect the injector connector.

CHECK THE INJECTION CONDITION
1.Carry out the procedure to prevent flow of the fuel (Refer to ).
caution Do not make fuel splash by covering fuel with waste and so on because the residual pressure is in the fuel pipeline.
2.Remove the fuel high-pressure hose at the delivery pipe side.

3.Remove the injector.
4.Assemble Injector Test Set (MD998706) of the special tool as shown in Fig.

  1. Install the injector to the installation hose for the injector and then fix it using Injector Holder (MB991976) of the special tool.
  2. Install Injector Test Adaptor (MD998741) of the special tool to another hose connected with the installation hose for the injector.
  3. Fold, band and tie up the rest of hose completely in order to prevent from fuel leakage because it is not used.
5.Install Injector Test Set (MD998706) of the special tool to the fuel high-pressure hose.
6.Connect the M.U.T.-III to the diagnosis connector.
7.Turn the ignition switch to "ON" position (but do not start the engine).
8.Select "Item No. 07" from M.U.T.-III actuator test and drive the fuel pump.

9.Connect Injector Test Harness (MB991607) of the special tool between the injector and battery, and then actuate the injector.
10.Check the fuel spray condition. The condition can be considered satisfactory unless it is extremely poor.
11.Stop actuating the injector. Check leakage from the injector nozzle. Turn the ignition switch to "LOCK OFF" position and then disconnect M.U.T.-III.
12.Actuate the injector until the fuel cannot flow. Draw the fuel out from the special tool.
13.Remove the special tool.
14.If the fuel spray condition is extremely poor or if there is the fuel leakage from the injector nozzle, replace the injector.
15.Install the injector and fuel high-pressure hose.