System (Line) Control Pressure Test
- Close valve on pressure gauge. With engine off, operate fuel pump. Pressure should rise to level specified in "Pressure Testing" chart.
- If pressure is too low, check fuel pump output. Disconnect fuel return line from fuel distributor and run a hose from fuel distributor to container. Operate fuel pump and measure output after 30 seconds. If not as specified in "Fuel Pump Flow" chart, check fuel lines, filter, accumulator and pump.Fuel Pump Flow Specifications
Application Flow in 30 Sec. oz. (cc) BMW, Peugeot, Porsche 24 (750) Audi, Saab, VW 30 (900) Mercedes-Benz 32 (1000) Volvo Turbo 35 (1050) All Others 27 (800) - If pressure is too high, check for kinked or blocked fuel return line. If lines are clear, system pressure regulator must be adjusted. Turn pump off, loosen return line fitting, and relieve pressure.
- Loosen line pressure regulator nut. Remove shims, spring(s) and plunger. Raise system pressure by adding shims; lower pressure by removing shims. Be sure "O" rings are in good condition. If plunger is scored or damaged, fuel distributor must be replaced.