TROUBLESHOOTING
This manual describes the basic 4Y-M vehicle (mechanical fuel injection system). For troubleshooting for the
electrical systems of the 4Y-E (electronic fuel injection system), refer to the troubleshooting pages for the separate
repair manual for each vehicle.
MECHANICAL TROUBLE
The causes of engine faults are divided into
3
factors of gasoline engines.
3
Factors of Gasoline Engines
I
3 factors Main functional parts
I
I
Good air-fuel mixture
(
Fuel tank, fuel pump, fuel strainer, carburetor, air governor etc.
I
I
Good compression
I
Engine body (Intake and exhaust valves, piston rings, cylinders etc.)
I
I
Good ignition
(
Distributor, spark plugs, resistive cord and ignition
The basics are as described above, however, since insufficient maintenance also gives rise to faults. Carry out pre-
inspections of the following items.
I
Pre-inspection items
I
I
Air cleaner
I
Air governor operating condition
I
Coolant
Engine oil
Battery and terminals
Spark plugs
Ignition timing
Idle speed status
List of Items
Fan belt Looseness in any engine part
Status
I
Insufficient power output (including hunting)
I
See PI-8
Fault
I
Page
Engine has trouble in starting or does not
start
Engine running rough
Abnormal combustion
Engine does not crank normally
Engine does not start easily, or does not start at all
Engine is rough, or stops, during idling
Cannot accelerate smoothly (including hesitation)
Engine overheats
Excessive fuel consumption
Abnormal engine noise, or noisy engine
See PI-3
See PI-4
See PI-5
See PI-6
I
After fire
I
See PI-12
-
-
Knocking
Run on
See PI-9
See PI-10
See PI-11
See PI-11
I
Noise that is often heard regardless of engine speed
I
See PI-15
Back fire
Noise that changes with operation of the clutch pedal
Noise that is often heard during idling
Noise that is often heard at a certain engine speed
See PI-12
See PI-13
See PI-13
See PI-14
Excessive engine oil consumption
-
See PI-16
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