System (Line) Control Pressure Test
- Close valve on pressure gauge. With engine off, operate fuel pump. Pressure should rise to level specified. See FUEL INJECTION PRESSURE TESTING table.
- 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. See Fuel Pump Output Specifications table. If not as specified, check fuel lines, filter, fuel accumulator, and fuel pump.FUEL PUMP OUTPUT SPECIFICATIONS
Application 30 Sec. Flow Rate: Oz. (cc) Audi 30 (900) - 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 piston is scored or damaged, fuel distributor must be replaced. See Fig 1 .