Initial Inspection (Visual Inspection)

A visual inspection for loose, disconnected, damaged, or improperly routed wires and hoses should be made prior to attempting to diagnose the fuel injection system. A visual inspection will help find these faults and save unnecessary test and diagnostic time. A through visual inspection includes the following:
1. Inspect battery cable connections for cleanliness and tightness. The top of the battery should be free of corrosion and dirt.

SBEC System Ground:

2. Inspect the engine control system ground connections on the side of the frame rail underneath the battery.

Power Distribution Center (PDC) And Diagnostic Connector:

Relay Location/Identification:

3. Inspect all power distribution center electrical connections. Inspect relays and distribution housing for physical damage and corrosion.
4. Inspect ignition coil electrical connections. Check secondary cables for proper routing, condition, and connections.
5. Check the air filter for obstructions and check the vacuum lines at the air cleaner cover for proper connections and condition.
6. Check the cruise control vacuum lines for connections, routing, and condition.
7. Check the brake booster vacuum hose connections and condition.
8. Check the air pre-heater hose connections and condition.
9. Check the air cleaner hot air door for obstructions and operation. Check the vacuum hose for proper connections, routing, and condition.

Air Cleaner Vacuum Motor:

10. Check the CrankCase Ventilation (CCV) fresh air and vacuum hoses for proper connections, condition, and routing.

Throttle Position Sensor (TPS)/Automatic Idle Speed (AIS) Motor:

11. Check the Throttle Position Sensor (TPS) and Automatic Idle Speed (AIS) motor electrical connections and check the wiring for damage.
12. Check the vacuum line connections at the intake manifold for proper connections and condition.

Manifold Absolute Pressure (MAP) Sensor:

13. Check the Manifold Absolute Pressure (MAP) sensor vacuum and electrical lines for proper connections and condition.

Engine Ground:

14. Check the engine ground strap connections.

EGR Control Valve and Electronic Transducer:

15. Check the EGR valve and Electric EGR Transducer (EET) vacuum hoses and electrical connections.

Crankshaft Timing Sensor:

Camshaft Timing Sensor:

16. Check the camshaft and crankshaft sensor wiring harnesses for proper connections and condition.
17. Check the throttle linkage, accelerator cable, throttle cable, and cruise control cable for binding, sticking, or damage.
18. Check the throttle return spring, replacing it if it is weak.
19. Check the injector harness connectors for proper connections and condition. Check the wiring harness for damage.
20. Check the fuel pressure regulator vacuum line for proper connection and condition, replacing it if necessary.

Coolant Temperature Sensor (CTS):

21. Check the coolant temperature sensor electrical connector for proper connection and condition.

Charge Temperature Sensor:

22. Check the charge temperature sensor electrical connector for proper connection and condition.
23. Check the radiator fan electrical connectors for proper connection and condition.
24. Check the starter motor electrical connections for looseness or corrosion.
25. Check the oxygen sensor connector for proper connection and condition.
26. Check the alternator wiring harness for proper connections and condition. Check the alternator drive belt for proper installation and adjustment.
27. Check the canister purge hoses for proper connections and condition.
28. Check the fuel pump electrical and fuel connectors for proper connections and condition.