Toyota Supra 1990 Manual page 36

EM-4 ENGINE MECHANICAL -
Troubleshooting
TROUBLESHOOTING
Problem
Possible cause
Remedy
Page
Engine overheats
Cooling system faulty
Troubleshoot cooling system CO-4
Incorrect ignition timing
Reset timing IG-20
Engine will not crank or Starting system faulty
Troubleshoot starting system ST-2
•
cranks slowly
Engine will not start/
Vacuum leaks
Repair as necessary
hard to start
•
PCV hoses
(cranks OK)
•
EGR valve
•
Intake manifold
•
Air intake chamber
•
Throttle body
•
ISC valve
Pulling in air between air flow meter and
Repair as necessary
throttle body
Ignition problems
Perform spark test
IG-5,10
•
Ignition coil
•
Igniter
•
(7M-GE)
Distributor
(7M-GTE)
Cam position sensor
High-tension cord disconnected or broken Inspect cord
IG-6, 11
No fuel supply to injector
Troubleshoot EF I system FI-10
•
No fuel in tank
•
Fuel pump not working
•
Fuel filter clogged
•
Fuel line clogged or leaking
EF I system problems
Repair as necessary
ISC system problem
Check ISC system
FI-106
Spark plugs faulty
Inspect plugs
IG-7
Low compression
Check compression
EM-20,21
Rough idle, stalls or
Vacuum leaks
Repair as necessary
misses
•
PCV hoses
•
EGR valve
•
I ntake manifold
•
Air intake chamber
• Throttle body
•
ISC valve
Pulling in air between air flow meter and
throttle body
Incorrect idle speed
Check ISC system
FI-106
Incorrect ignition timing
Reset timing
IG-20
Ignition problems
Perform spark test
IG-5,10
•
Ignition coi I
•
Igniter
•
(7M-GE)
Distributor
(7M-GTE)
Cam position sensor
High-tension cord faulty Inspect cord
IG-6, 11
EFI system problems
Repair as necessary