VicTDI
Veteran Member
Was looking for info on the PD technology. I don't think this is written specifically for the 2004s but hopefully the info is correct. Perhaps those of you in the know out there can confirm. Thanks.
"Other VW TDI models with the 1.9 litre 4-cylinder of 115 hp or 150 hp, and the 1.2 litre and 1.4 litre 3-cylinder engines, use a so-called "pumpe-deuse" (German) or "pump-nozzle" (English translation) system. In these engines, each cylinder has its own small high-pressure fuel pump which is actuated by the same camshaft that operates the intake and exhaust valves. Fuel is delivered to each pump-nozzle by a low-pressure pump serving the same function as the internal vane pump in the distributor-type system. As the engine cylinder approaches the end of the compression stroke, the main pump plunger advances, pressurizing the fuel. A solenoid valve adjacent to each pump-nozzle is normally open and bypasses the fuel. When the solenoid valve is energized, the bypass passage is closed and the fuel is forced to an extremely high pressure and through the injection nozzle. At the end of the required injection period, the solenoid valve de-energizes and any remaining fuel pumped by the plunger bypasses the nozzle. Thus, fuel is injected as long as the solenoid is energized, allowing full control of injection timing and duration. This system has the significant advantage of eliminating the separate high-pressure fuel lines from the pump to the nozzle because it is all built into a single unit, thus giving better control of the injection cycle."
"Other VW TDI models with the 1.9 litre 4-cylinder of 115 hp or 150 hp, and the 1.2 litre and 1.4 litre 3-cylinder engines, use a so-called "pumpe-deuse" (German) or "pump-nozzle" (English translation) system. In these engines, each cylinder has its own small high-pressure fuel pump which is actuated by the same camshaft that operates the intake and exhaust valves. Fuel is delivered to each pump-nozzle by a low-pressure pump serving the same function as the internal vane pump in the distributor-type system. As the engine cylinder approaches the end of the compression stroke, the main pump plunger advances, pressurizing the fuel. A solenoid valve adjacent to each pump-nozzle is normally open and bypasses the fuel. When the solenoid valve is energized, the bypass passage is closed and the fuel is forced to an extremely high pressure and through the injection nozzle. At the end of the required injection period, the solenoid valve de-energizes and any remaining fuel pumped by the plunger bypasses the nozzle. Thus, fuel is injected as long as the solenoid is energized, allowing full control of injection timing and duration. This system has the significant advantage of eliminating the separate high-pressure fuel lines from the pump to the nozzle because it is all built into a single unit, thus giving better control of the injection cycle."
