Repair instructions Venting the fuel system Signals to engine Pre-heating and post heating time The EDC system is equipped with software to control pre-heating of the engine before starting, and subsequent warming up of the engine after starting. Please refer to the “Operating an engine with EDC system, starting and stopping“ chapter. TWD740VE TWD1231VE 1. Vent screw on filter bracket 2. Hand pump 3. By-pass valve 4. Injector union Input signals There are three ways to control engine speed: NOTE! The fuel system must be vented after the fuel filter is changed, or after filling the fuel tank when it has been run dry. Accelerator potentiometer:
0.4 to 2–2.5 k Ω (The potentiometer must not go below 400 Ω ). Must be cali- brated, please refer to the “Calibrating the accelerator“ chapter. 0.4 to 2 – 2.5 k Ω 1. Put a suitable vessel underneath the fuel fil- ter. Open the vent screw (1) on the filter bracket. 4. If the injection pump still needs to be vented, loosen the connection for the by-pass valve (3) at the pump (the pump can also be vented by loosening the unions at the injectors (4)) until air-free fuel flows out. Tighten the unions while fuel is flowing out. Pump another 10 to 20 strokes, to build up a suitable supply pres- sure. 100 – 300 Ω 100 – 300 Ω 2.
Pump up fuel with the hand pump on the supply pump (2) until fuel flows out, free from bubbles. Tighten the vent screw while fuel is flowing out. 400 – 700 Ω 3. Pump another 10 to 20 strokes with the vent screw closed, to build up a suitable supply pressure. Further venting is not normally needed. 5. Start the engine and check carefully that no leakage occurs. 2* 3* 4* * According to the engine connector on the higher-level cable electrical system, please refer to the “Wiring diagrams“ chapter. 30 23