BOSCH Diesel Fuel Injection - MERCEDES-BENZ: Description: Notes
7977-79 FUEL SYSTEM SPECIFICATIONS
| Application | Specifications | |
|---|---|---|
| Idle Speed | 650-850 RPM | |
| Fuel Pump | ||
| Delivery Pressure | ||
| At Idle Speed | 8.5-11.4 psi (0.6-0.8 kg/cm2 ) | |
| At 3000 RPM | 11.4 psi (0.8 kg/cm2 ) | |
| Fuel Pump | ||
| Final Delivery Pressure | ||
| At Idle Speed | 15.6 psi (1.1 kg/cm2 ) | |
| At 3000 RPM | 18.5 psi (1.3 kg/cm2 ) | |
| Start of Delivery | 24 Degrees BTDC | |
| Nozzle Opening Pressure | ||
| 240D & 300D | 1635-1750 psi (115-123 kg/cm2 ) | |
| 300SD Turbo | 1958-2074 psi (135-143 kg/cm2 ) | |
The Bosch Diesel Fuel injection system consists of pre-filter, main fuel filter, fuel injection pump, centrifugal governor, automatic altitude compensating device, vacuum control unit, injection nozzles, and glow plugs.
Fuel is pumped from fuel tank, through a pre-filter and main fuel filter into suction chamber of injection pump. Pump's camshaft operates injection pump plungers, which force fuel through delivery valves, reverse-flow dampening valves, and pressure lines to fuel injection nozzles. When pressure stroke is completed, spring-loaded valves close pressure lines. Plungers return to original position.