Troubleshooting - Toyota Land Cruiser 1988 Repair Manual

EFI SYSTEM -Troubleshooting Fl-9
FI0482
TROUBLESHOOTING
TROUBLESHOOTING HINTS
1. Engine trouble are usually not caused by the EFI system.
When troubleshooting, always first check the condition
of the other systems.
(a) Electronic source
• Battery
• Fusible links
• Fuses
(b) Body ground
(c) Fuel supply
• Fuel leakage
• Fuel filter
• Fuel pump
(d) Ignition system
• Spark plugs
• High-tension cords
• Distributor
• Ignition coil
• Igniter
(e) Air induction system
• Vacuum leaks
(f) Emission control system
• PCV system
• EGA system
• AI system
(g) Others
• Ignition timing ( ESA system)
• Idle speed (ISC system)
• etc.
2. The most frequent cause of problems is simply a bad
contact in wiring connectors. Always check that connec,.
tions 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 com-
pletely and locked ..
(c) Check to see that there is no signal change when the
connector is slightly tapped or wiggled.
3. Sufficiently troubleshooting for other causes before re-
placing the ECU, as the ECU is of high quality and ex-
pensive.