Quantum L4-1588cc 1.6L DSL SOHC Turbo (1982)
Diesel MFI Pump: Description and Operation
Low Pressure Fuel Delivery
General Functions
Bosch VE fuel-injection systems have a vane-type fuel-supply pump that draws fuel from the fuel tank and delivers it to the injection-pump cavity.
The supply pump delivers a virtually constant flow of fuel. To obtain a defined pressure level proportional to engine speed, a pressure-control valve is
required. With this valve, pressure can be set to correspond to a particular engine speed. This means that the pump-cavity pressure increases along with
rising engine speed.
A portion of the fuel flows through the pressure-control valve and returns to the suction side. For cooling and self-ventilation of the distributor
injection pump, some fuel also flows through the overflow restriction on the governor cover and back to the fuel tank.
Supply Pump
Fig. 3 Supply Pump
The supply pump, Fig. 3, surrounds the input shaft, its impeller concentric with the shaft and driven by a Woodruff key. In turn, the impeller runs
inside an eccentric ring fixed to the housing.
