Fuel Pump Pressure Test

1. Remove air cleaner and plug THERMAC vacuum port on throttle body unit.
2. Remove fuel line between TBI unit and fuel filter. Use a suitable back-up wrench to hold flare nut on throttle body when removing line.
3. Install fuel pressure gauge J-29658 or equivalent, between throttle body and filter.
4. Check pressure reading with engine running. Fuel pressure should be between 9 and 13 psi.
5. De-pressurize fuel system, remove pressure gauge and reinstall fuel line.
6. Start engine and check for fuel leaks.
7. Remove plug from THERMAC vacuum port and install air cleaner.


*** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 90-6C-89, Dated 9/90

Some 1985-90 engines equipped with 2.5L, 2.8L, 4.3L, 5.0L, 5.7L or 7.4L may experience a condition where fuel delivery is interrupted to the engine causing a "no start condition". This condition may be caused by deterioration of the in-tank fuel pump coupler hose located between the fuel pump sending unit and the fuel pump. This condition may be repaired by replacing the original coupler hose with a new VITON coupler hose kit P/N 25028041. The kit consist of a new VITON hose and two clamps.