Fuel System & Engine Control System: General: Troubleshooting

When troubleshooting an engine malfunction, it is important to start with an inspection of the basic systems. If one of the following conditions exists; engine start failure, unstable idling or poor acceleration, begin by checking the following basic systems.

1. Power supply
   • Battery
   • Fusible link
   • Fuse
2. Body ground
3. Fuel supply
   • Fuel line
   • Fuel filter
   • Fuel pump
4. Ignition system
   • Spark plug
   • High-tension cable
   • Ignition coil
5. Emission control system
   • PCV system
   • Vacuum leak
   • EGR system and EVAP. control system
6. Others
   • Ignition timing
   • Idle speed

Malfunctions in the MPI system are often caused by poor connections in the harness connectors. It is important to check all harness connectors and verify that they are securely connected.