Observe the precautions before working on any component in the fuel system. A cold spray will be required to cool the expansion element in the following procedure. The fast idle speed is controlled by an electrically heated expansion element located on the top of the injection pump. With the engine cold, the idle speed is increased to 900 ± 50 rpm, and after a maximum period of two minutes, the engine speed returns to normal. The engine must be at normal operating temperature before carrying out this procedure, and all electrical accessories must be switched off. Apply the handbrake and select neutral, ensuring the cold start knob is pushed in to the fully off position. Start the engine and allow it to idle. Disconnect the wiring from the expansion element, then use the cold spray to cool the element to a temperature below 30° C, causing the engine idle speed to increase to 900 ± 50 rpm. If the fast idle speed is incorrect, loosen the locknut on the expansion element and turn the element until the correct idle speed is obtained, then tighten the locknut. Connect the wiring to the element and check that the engine speed returns to normal within two minutes. If the expansion element does not function correctly, it must be renewed.