Initial Inspection and Diagnostic Overview

TROUBLESHOOTING
TROUBLESHOOTING HINTS
1. Engine troubles are usually not caused by the EFI system. When troubleshooting, always first check the condition of these systems.
(a) Electronic source
^ Battery
^ Fusible links
^ Fuses
(b) Fuel supply
^ Fuel leakage
^ Fuel filter
^ Fuel pump
(c) Ignition system
^ Spark plug
^ High-tension cord
^ Distributor
^ Igniter and ignition coil
(d) Air intake system
^ Vacuum leaks
(e) Emission control system
^ EGR system
^ PCV system
(f) Others
^ Ignition timing
^ Idle speed
^ etc.





2. The most frequent cause of problems is simply a bad contact in wiring connectors. So always make sure that connections are secure.
When inspecting the connector, pay particular attention to the following points:
(a) Check to see that the terminals are not bent.
(b) Check to see that the connector is pushed in completely and locked.





(c) Check to see that there is no signal change when the connector is slightly tapped or wiggled.
3. Sufficiently troubleshoot for other causes before replacing the ECU. The ECU is of high quality and it is expensive.





4. Use a volt/ohmmeter with a high impedance (10 K ohms/V minimum) for troubleshooting an electrical circuit.