The fuel system is designed to use fuel to cool and lubricate the injection pump and injectors. Fuel is contin
ually vented from the injection pump and a small amount of fuel leaks by the injector needle valve during injection.
This fuel is returned to the supply tank by the fuel drain manifold.
Restriction of the fuel drain manifold can affect the Lucas CAV D PA/D PS fuel injection pump metering controls and
the operation of the injectors. Restricting the fuel drain manifold raises the case pressure of the fuel injection
pump which can prevent injection.
If the engine will restart after a waiting period following an unexplained shut down, look for a restriction of the man-
ifold drain line.
NOTE: Restriction can cause the fuel temperature to rise reducing power from the engine.
