Sprint Turbo
- Relieve fuel system pressure. Connect fuel pressure gauge between fuel filter and fuel rail with "T" Fitting (J 34730-1-75). Start engine. With engine idling, fuel pressure should be 25-33 psi (1.7-2.3 kg/cm2 ).
- Disconnect vacuum hose from fuel pressure regulator. With engine idling, fuel pressure should be 35-43 psi (2.5-3.0 kg/cm2 ). Turn engine off. With engine off, fuel pressure should be 22-32 psi (1.5-2.2 kg/cm2 ).
- Connect a vacuum pump to fuel pressure regulator. Start engine. Apply 19 in. Hg to fuel pressure regulator. With engine idling, fuel pressure should be 34-42 psi (2.4-2.9 kg/cm2 ).
- If fuel pressure is less than specified with engine idling, check for leakage at fuel feed line, restricted fuel filter or fuel line, defective fuel pump or fuel pressure regulator. If fuel pressure is more than specified with engine idling, check fuel pressure regulator, restricted pressure regulator vacuum hose or restricted fuel lines. If fuel pressure is less than specified with engine off, check for defective check valve in fuel pump, leakage in fuel feed hose, defective fuel pressure regulator or leaking injector.