1. Check that the air cleaner and all vacuum lines are properly installed and in good condition. Make sure there are no signs of leaks in the intake air path.
2. Apply the parking brake and chock the wheels. Switch off all onboard electrical consumers and check that the ignition timing is set correctly (see chapter Engine electrical equipment).
3. The engine must be warmed up to normal operating temperature, which guarantees automatic shutdown of fast idling.
4. Make sure the transmission is in the «R».
5. The required accuracy of measuring the engine speed when checking its idle speed can only be provided by a remotely connected digital tachometer, connect the device strictly in accordance with the manufacturer's instructions.
Gas engine
1. Connect a tachometer. Connect the probe of the tachometer tester to the terminal «IG» (-) diagnostic socket.
Attention! Do not touch the ground tachometer wire, as this may damage the coil assembly.
2. Start the engine and increase the engine speed to 1000 rpm; holding it for about 5 seconds. Release the gas pedal.
3. Read the tachometer readings and compare them with the requirements Specifications. If the idle speed does not meet the requirements Specifications, the fault is most likely in the electronic idle control system (ETCS). Idle speed on fuel injected engines (EFI) are controlled by the ECM, there is no mechanical adjustment in this system.
Diesel engine
Minimum RPM Adjustment
1. Make sure that when the gas pedal is released, the injection pump control lever touches the minimum idle speed adjustment screw (refer to accompanying illustration). Otherwise, adjust the drive lever.
2. Start the engine, check the idle speed, compare the test results with the requirements Specifications.
3. To adjust, disconnect the injection pump lever drive and set the minimum idle speed by turning the screw to the position corresponding to the middle of the specified range (refer to accompanying illustration).
4. Tighten the adjusting screw locknut and check the idle speed again.
5. Connect the control lever actuator and adjust if necessary.
Adjustment of the maximum turns
1. Make sure that when the gas pedal is depressed, the injection pump control lever touches the maximum speed adjustment screw (refer to accompanying illustration). Otherwise, adjust the drive lever.
2. Start the engine, fully depress the gas pedal, measure the maximum crankshaft speed and compare the measurement results with the requirements Specifications.
Note. Do not allow the engine to run at maximum speed for more than 5 seconds. Adjust only when the minimum idle speed is adjusted.
3. To adjust, disconnect the accelerator rod, cut off the seal of the adjusting screw and use a special key to release its locknut. Set the maximum idle speed by turning the screw to the position corresponding to the middle of the specified range (refer to accompanying illustration).
4. Tighten the adjusting screw locknut, adjust the minimum idle speed, and check the maximum speed again.
5. Connect the accelerator link and adjust the drive if necessary. Install a new seal on the adjusting screw.