SAAB WIS ONLINE

Fuel flow

Fuel flow


When the engine is started and the fuel injection pump starts to operate, the feed pump that is integrated in the fuel injection pump sucks fuel from the container located inside the fuel tank. The fuel is sucked via a pipe located in the bottom of the container and is then passed on to the engine's fuel pump via a fuel filter fitted on the side of the fuel tank.

The return fuel, i.e. the fuel that is not used, flows back to the fuel tank where it drives a negative ejector located in the fuel tank. In turn, the ejector fills the container from which the diesel pump sucks fuel. Put simply, an ejector is a cylinder with three openings, one at each end and one in the wall of the cylinder. When fuel flows through the cylinder (in at one end and out the other), negative pressure is created at the hole in the cylinder wall. The negative pressure is used to suck the fuel from the fuel tank and keep the container full, which means that the ejector starts to fill the container as soon as the engine is started so that there is always fuel available for the suction side.

Thanks to the fuel injection pump's feed pump sucking fuel from the container, the supply of fuel is ensured during cornering and acceleration even when only small amounts of fuel are remaining in the tank.

The fuel pump also contains a control module that, along with the PSG 16 control module, calculates the volume of fuel to be injected into the cylinders.

For further information refer to PSG 16 control module .