Service Manual

APPENDIX 17-53
Troubleshooting Guide (except DFI)
Choke knob left pulled out (DFI)
Throttle body assy O-ring dam age
Air cleaner duct loose
Air cleaner O-ring damaged
Fuel pump (DFI) trouble
Compression low:
Spark plug loose
Cylinder head not sufficiently tightened
down
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or
sticking)
Piston ring/groove clearance excessive
Cylinder head warped
Cylinder head gasket damaged
Valvespringbrokenorweak
Valve not seating properly (valve bent,
worn, or carbon accumulation on the
seating surface)
KACR sticks open (engine stalls when mov-
ing off)
HLA seizure
Backfiring when deceleration:
Air switching valve broken
Air switching valve lead damaged
Air suction valve trouble
Other:
IC igniter in ECU trouble
Engine oil viscosity too high
Drive train trouble
Final gear case oil viscosity too high
Brake dragging
Engine overheating
Clutch slipping
Air suction valve trouble
Air switching valve trouble
Air switching valve lead damaged
Poor Running or No Power at High
Speed:
Firing incorrect:
Spark plug dirty, broken, or maladjusted
Spark plug cap or high tension wiring trou-
ble
Spark plug cap shorted or not in good con-
tact
Spark plug incorrect
IC igniter in ECU trouble
Crankshaft sensor trouble
Ignition coil trouble
Fuel/air mixture incorrect:
Choke knob left pulled out (DFI)
Air cleaner clogged, poorly sealed, or miss-
ing
Air cleaner duct loose
Air cleaner O-ring damaged
Water or foreign matter in fuel
Throttle body assy loose
Throttle body assy O-ring damage
Fuel to injector insufficient (DFI)
Fuel tank air vent obstructed
Fuel line clogged
Fuel pump trouble (DFI)
Compression low:
Spark plug loose
Cylinder head not sufficiently tightened
down
Cylinder, piston worn
Piston ring bad (worn, weak, broken, or
sticking)
Piston ring/groove clearance excessive
Cylinder head gasket damaged
Cylinder head warped
Valve spring broken or weak
Valve not seating properly (valve bent,
worn, or carbon accumulation on the
seating surface.)
KACR sticks open (engine stalls when mov-
ing off)
HLA seizure
Knocking:
Carbon built up in combustion chamber
Fuel poor quality or i ncorrect (Be sure to
use high-octane gasoline recommended
by Owner ’s Manual)
Spark plug incorrect
IC igniter in ECU trouble
Miscellaneous:
Throttle valves won’t fully open
Brake dragging
Clutch slipping
Engine overheating
Engine oil level too high
Engine oil viscosity too high
Drive train trouble
Final gear case oil viscosity too high
Air suction valve trouble
Air switching valve t rouble
Air switching valve lead damaged
Catalytic converters melt down due to muf-
fler overheating (KLEEN)
Overheating:
Firing incorrect:
Spark plug dirty, broken, or maladjusted
Spark plug incorrect
IC igniter in ECU trouble
Muffler overheating:
For KLEEN, do not run the engine even if
with only one cylinder misfiring or poor
running (Request the nearest service fa-
cility to correct it)
For KLEEN, do not push-start with a dead
battery (Connect another full-charged