Part 1 of 3

Chart A-7A:

Fuel Injection Circuit:

CIRCUIT DESCRIPTION:

When the ignition switch is turned to the "ON" position, the Electronic Control Module (ECM) will energize the fuel pump relay for 3 seconds, allowing for fuel pump operation. When the fuel pump relay is de-energized, the fuel pump stops operating. If the engine is being cranked, or is running, the fuel pump will continue to operate, as long as the ECM is receiving ignition reference pulses. If the ignition reference pulses are not detected, the fuel pump will stop after 3 seconds.

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. Checks fuel pump operation with ignition switch in the "ON" position.

2. Checks fuel pump relay switch for power.

3. Checks for faulty ECM or improper fuel pressure.

4. Checks fuel pump circuit

5. Checks for an open PNK wire.

6. Checks fuel pump relay coil for power.

7. Checks for faulty fuel pump or an open BLK wire.

8. Checks for faulty fuel pump relay.

9. Checks for faulty ECM or an open PNK/WHT wire.

DIAGNOSTIC AIDS:

Visual inspection of wiring and connectors should be made if an intermittent problem exists.

FUEL PRESSURE RELIEF PROCEDURE:

CAUTION: To reduce the risk of fire and personal injury, it is necessary to relieve the fuel system pressure before servicing the fuel system. After relieving system pressure, a small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting, to catch any fuel that may leak out. Place the towel in an approved container when disconnect is completed.

FUEL PRESSURE GAUGE INSTALLATION:

1. Loosen fuel filler cap to relieve tank vapor pressure.

2. Remove fuse and relay box cover and engine coolant reservoir from its bracket.

3. Disconnect fuse and relay box from fender (two screws).

4. Disconnect fuel pump relay from fuse and relay box connector.

5. crank engine and allow to stall. Crank engine for an additional 3 seconds to assure relief of any remaining fuel pressure.

6. Disconnect negative battery cable.

7. Remove air cleaner assembly.

8. Remove fuel feed hose from throttle body.

9. Install fuel rail adaptor J 34730-75 or equivalent, to throttle body.

10. Install fuel pressure gauge J 34730-1 or equivalent, to J 34730-75 fuel rail adapter.

11. Install air cleaner assembly.

12. Reconnect negative battery cable.

13. Install fuel pump relay in its connector and connect fuse and relay box to fender (two screws).

14. Install fuse and relay box cover and engine coolant reservoir to its bracket and tighten fuel filler cap.

NOTE: Be sure to relieve fuel pressure again when removing the fuel pressure gauge.