Fuel System - Operation and Tests/Distributor Injection Pump FUEL TRANSFER PUMP OPERATION (DISTRIBUTOR INJECTION PUMP) Fuel flows from the fuel tank at gravity pressure to the inlet side of the diaphragm-type pump. This pump increases the fuel pressure to 20 to 30 kPa (0.20 to 0.3 bar ; 2.9 to 4.35 psi) at slow idle speed and forces fuel through the filter to the fuel injection pump. 220 4 CD30334 -UN-17FEB95 The fuel transfer pump is operated by an eccentric lobe on the engine camshaft. CD,3274,G220,3 -19-04JAN99 CTM3274 (01JUL99) 220-4 Saran Liter Engines 060799 PN=343