Component description of fuel pump - GF47.20-P-2000SM

ENGINE 113.986 in MODEL 215, 220

ENGINE 113.987 in MODEL 209

ENGINE 113.988 in MODEL 203

ENGINE 113.989 in MODEL 171

Fig 1: Identifying Fuel Pump - Two-Stage Flow Pump In Model 203, 209, 215 & 220

Fig 2: Identifying Fuel Pump - Helical Spindle Pump In Model 171

The fuel pump assembly is located at the bottom in the fuel tank.

Task

The fuel pump supplies an adequate quantity of fuel at the required pressure to the fuel injection system (fuel distribution tube).

Fig 3: Identifying Screw Spindle Pump Design

Function of helical spindle pump

The rotating spindle (1) delivers the fuel to the fuel filter by the centrifugal force effect. In this case the fuel pump delivers more fuel than the engine needs in total in order to maintain the pressure in the fuel system in all operating states. As a result of this circulation relatively cool fuel is always available for injection (avoids the formation of vapor bubbles).

A pressure relief valve (4) is integrated in the fuel pump in order to limit the pressure.

The check valve (3) in the fuel pump decouples the fuel system from the fuel tank by preventing fuel from flowing back through the disconnected fuel pump to the fuel tank.

Fuel pump control

MODEL 171

The fuel pump assembly (M3) is controlled via the fuel pump relay (N10/2kA) by the ME control unit (N3/10).

Model 203, 209

The fuel pump (M3) is controlled via the fuel pump relay (N10/2kA) by the ME control unit (N3/10).

Model 215, 220

The fuel pump (M3) is controlled via the fuel pump relay (K40/5kT) by the ME control unit (N3/10).