Initial Inspection and Diagnostic Overview

Before diagnosing or servicing the fuel injection system, perform a visual inspection for loose, disconnected, or misrouted wires and hoses. A thorough visual inspection that includes the following checks saves unnecessary test and diagnostic time.

Remote Battery Terminals and PCM Connectors:

1. Inspect remote battery cable connections. Be sure they are clean and tight. Clean corroded terminals.
2. Verify that the PCM's 240-way connectors are fully inserted into their sockets on the PCM.
3. Open the Power Distribution Center (PDC). Check for blown fuses. Ensure the relays and fuses are fully seated in the PDC. A label on the underside of the PDC cover shows the locations of each relay and fuse.
4. Inspect accelerator cable, and cruise control cable (if equipped) connections. Check their connections to the throttle arm of the throttle body for any binding or restrictions.

Idle Air Control Motor and Throttle Position Sensor:

5. Check the electrical connections at the idle air control motor and throttle position sensor.

PCV Valve:

6. Check hose connections between the PCV valve, vacuum port~intake manifold.

MAP Sensor and Intake Air Temperature Sensor:

7. Inspect the electrical connections at the intake air temperature sensor and the MAP sensor.

Fuel Injector:

8. Inspect the fuel injector electrical connections.

Ignition Coil and Spark Plugs:

a. Inspect the ignition coil electrical connector. Ensure the spark plug insulators are firmly seated over the spark plugs.

Proportional Purge Solenoid:

11. Inspect the electrical and hose connections at the proportional purge solenoid.
12. Check electrical connection to the radiator fan.
13. Inspect system body grounds for loose or dirty connections.
14. Inspect air cleaner filter element. Replace as necessary. Check air induction system for restrictions.

Knock Sensor:

15. Check electrical connection at the knock sensor.

Camshaft Position Sensor:

16. Check electrical connections at the camshaft position sensor.

Engine Coolant Temperature Sensor:

17. Check electrical connections at the engine coolant temperature sensor.

Electronic EGR Transducer:

18. Check electrical connector at Electronic EGR Transducer. Inspect vacuum and back pressure hoses at the solenoid and transducer for leaks.
19. Inspect electrical connections at the generator. Check the generator belt for glazing or damage.

Crankshaft Position Sensor-Typical:

20. Inspect electrical connector at the crankshaft position sensor.

Output Speed Sensor-Automatic Transmission:

21. Check electrical connection at the vehicle speed sensor.

Power Steering Pressure Switch:

22. Check electrical connection at the power steering pressure switch on the power steering gear housing.
23. On vehicles with automatic transaxles, check the electrical connections at the Transmission Range Sensor (TRS).

Oxygen Sensor 1/1 Upstream:

Oxygen Sensor 2/1 Downstream:

24. Inspect the electrical connections at the upstream and downstream heated oxygen sensors.

Fuel Pump Module Electrical Connector:

25. Inspect the fuel pump module electrical connection in the trunk for corrosion or damage
26. Inspect the connections to the speed control servo, if equipped. Refer to the Vehicle Speed Control.