MARUTI SUZUKI 800, Service Manual

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ENGINE DIAGNOSIS 6-13
Condition Possible Cause Reference Item
Excessive detonation
(The engine makes
sharp metallic knocks
that change with
throttle opening.
Sounds like pop corn
popping.)
Engine overheating
Ignition system out of order.
Faulty spark plug
Improper ignition timing
Fuel system out of order.
Clogged fuel filter and fuel lines
Engine and emission control system
Refer to “Overheating” Section.
Spark plugs in Section 6F.
Ignition timing in Section 6F.
Fuel pressure check in Section 6E1.
out of order.
Faulty ECT sensor or MAP sensor
Faulty injector
Faulty ECM
Others
Excessive combustion chamber deposits
ECT sensor or MAP sensor in Section
6E1.
Fuel injector in Section 6E1.
Inspection of ECM and its circuit in Sec-
tion 6E1.
Piston and cylinder head cleaning in
Section 6A or 6A1.
Overheating Inoperative thermostat
Poor water pump performance
Clogged or leaky radiator
Improper engine oil grade
Clogged oil filter or oil strainer
Poor oil pump performance
Dragging brakes
Slipping clutch
Blown cylinder head gasket
Thermostat in Section 6B.
Water pump in Section 6B.
Radiator in Section 6B.
Engine oil and oil filter change in
Section 0B.
Oil pressure check in Section 6A or 6A1.
Oil pressure check in Section 6A or 6A1.
Diagnosis in Section 5.
Diagnosis in Section 7C.
Cylinder head inspection in Section 6A
or 6A1.
Poor gasoline
mileage
Ignition system out of order.
Faulty spark plug (improper gap, heavy
deposits, and burned electrodes, etc.)
Engine and emission control system
out of order.
Fuel pressure out of specification
Faulty TP sensor, ECT sensor or MAP
sensor
Faulty injector
Faulty ECM
Low compression
Others
Poor valve seating
Dragging brakes
Slipping clutch
Thermostat out of order
Improper tire pressure
Spark plugs in Section 6F.
Diag. Flow Table B-3 in Section 6E1.
TP sensor, ECT sensor or MAP
sensor in Section 6E1.
Fuel injector in Section 6E1.
Inspection of ECM and its circuit in Sec-
tion 6E1.
Previously outlined.
Valves inspection in Section 6A or 6A1.
Diagnosis in Section 5.
Diagnosis in Section 7C.
Thermostat in Section 6B.