Idle Speed Adjustment

Location of idle speed adjusting bolt

Use two wrenches to loosen or tighten the locknut.
The idle speed fuel quantity is correctly adjusted when the injected fuel quantity at idle is properly set. This adjustment must be carried out only with special equipment. However, general checking and temporary adjustment to allow the engine to start can be performed by following the instructions below. Correct idle speed can be obtained only when the valve clearances and injection timing are correctly adjusted. Connect a diesel engine tachometer in accordance with the manufacturer's operating instructions.
Before adjusting the idle speed, warm up the engine to normal operating temperature.

PROCEDURE
1. Switch off all electrical loads. The cooling fan must not run. The air cleaner must be installed.
2. Start the engine and read the idle speed. If it is more than 700 rpm, check whether the setting lever touches the adjusting screw with the accelerator pedal fully depressed. If not, adjust the idle speed.
3. Loosen the locknut of the idle speed adjusting screw at the location shown in the illustration (using an open-end wrench), and with a second wrench turn the adjusting bolt until the specified idle speed is obtained. Retighten the locknut.
4. Increase the engine speed and check that the engine returns to idle speed after the accelerator pedal is released. If it does not, the accelerator linkage length must be adjusted. With the accelerator pedal released, the lever of the high-pressure fuel injection pump must contact the end of the adjusting bolt.