Visual Inspection

ELECTRICAL CONNECTIONS
Terminals in connectors must lock together. Look for connectors that are not fully plugged into each other or terminals that are not fully plugged into insulator. Also make sure the wiring between each connector, and where it goes into the convolute of the harness, is not pinched behind any screws, bolts or rubbing on metal, which would result in a short to ground.









HOSE AND VACUUM LINE CONNECTIONS
All hose and vacuum line connectors must be fully and firmly fitted at their connections. Also, they cannot be pinched anywhere along their routing. Look for hoses and vacuum lines that are not fully plugged in, or are pinched, melted or cut. Also, make sure hoses are not egg-shaped at their connection points causing a leak.

Electrical Connections (Under Hood)
- Battery Cables (Not Shown)
- Engine to Firewall Ground Strap (Not Shown)
- Spark Plug Wires (Not Shown)
- Fuses and Fusible Links (Not Shown)

Passenger Compartment





- ECU/MPI Control Unit





- MPI Control Relay
- Fuse Block (Not Shown)

Underbody Connection
- In-Tank Fuel Pump

The following are the recommended categories that should be used:
1. Engine Will Not Start -- Test numbers begin with NS for no start.
- Visual Inspection
- No Start Tests
2. Cold Driveability Problems -- Test numbers begin with DR for driveability.
- Visual Inspection
- Driveability Tests
3. Warm Driveability Problems -- Test numbers begin with DR for driveability.
- Visual Inspection
- Driveability Tests

Replacing Components
Before replacing any vehicle component, inspect connector or connectors for pin or cavity damage that may result in a poor connection or an open circuit.

The following additional items should be checked as possible causes:
1. Engine Vacuum - Must be at least 13 inches in neutral.
2. Engine Valve Timing - To specifications.
3. Engine Compression - To specifications.
4. Engine Exhaust System - Must be free of any restrictions.
5. Engine PCV System - Must flow freely.
6. Engine Drive Sprockets - Cam and crankshaft.
7. Torque Converter Stall Speed - To specifications.
8. Power Brake Booster - No internal vacuum leaks.
9. Fuel Contamination - High alcohol and water content.
10. Fuel Injectors - Rough idle may be caused by injector control wire not connected to correct injector.
11. Technical Service Bulletins - Any that may apply to vehicle.
12. Engine Secondary Ignition Check - Any abnormal scope pattern.

Any one or more of these items can give a driveability related problem. They cannot be overlooked as possible causes.