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18 ENGINE MANAGEMENT SYSTEM 18 DESCRIPTION AND OPERATION ELECTRONIC UNIT INJECTOR (EUI) The EUI’s are located in the top of the engine inside the camshaft cover. There is one EUI per cylinder. They inject Using an injection timing map within its memory and information from the CKP sensor the ECM is able to 2 ) on pre EU3 models, and 1750 bar (25,500 lbf.in 2 ) on EU3 models . At this limit the pintle lifts off its seat allowing the fuel to inject into the combustion chamber. The ECM de-energises the spill valve to control the quantity of fuel The electrical circuit that drives the EUI works in two stages depending on battery voltage. If battery voltage is Input / Output 2 ). Each of the EUI’s is operated mechanically by an overhead camshaft to enable injection pressures of up to 1500 bar (22,000 lbf.in 2 ) on pre EU3 models, and 1750 bar (25,500 lbf.in 2 ) on EU3 models, to be achieved. The ECM controls the EUI’s to ensure that fuel delivery is precise and as intended. The EUI’s earth paths are as follows: • EUI 1 (C0522-1) via the ECM (C0158-25) on a yellow wire. • EUI 2 (C0523-1) via the ECM (C0158-26) on a yellow/brown wire. • EUI 3 (C0524-1) via the ECM (C0158-27) on a yellow/blue wire. • EUI 4 (C0525-1) via the ECM (C0158-24) on a yellow/red wire. • EUI 5 (C0526-1) via the ECM (C0158-1) on a yellow/purple wire. |