Fuel Pump: Description and Operation

Fuel Pumps







The fuel tank of the 911 Turbo (997) has 2 fuel pumps which are integrated into the common pump chamber (tandem pump). The fuel pump 1 delivers 1 qt. (1.1 liters) in 30 seconds, and fuel pump 2 delivers 1.4 qts. (1.5 liters) in 30 seconds. The two fuel pump relays are activated as required by way of switching points in the DME control unit.

Fuel pump 1 runs with a tank content of less than 13.7 gal. (52 liters). Fuel pump 2 is activated when a computed fuel requirement of greater than 26 gal/h (100 l/h).

Fuel pump 2 runs with a tank content of greater than 13.7 gal (52 liters). Fuel pump 1 is activated when a computed fuel requirement of greater than 37 gal/h (140 l/h).

The fuel is pumped out of the tank pockets by the two sucking jet pumps. The high-pressure sucking jet pump on the right side of the vehicle is supplied only by fuel pump 1. The low-pressure sucking jet pump on the left side of the vehicle is operated by one or both pumps depending on the fuel level and load condition. The quantity of fuel delivered by both fuel pumps can be checked as described in the Technical Data.