Suzuki Wagon R Plus RB310, Service Manual

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ENGINE MECHANICAL (M13 ENGINE) 6A2-7
Timing retarding
When the duty ratio of the signal output from the ECM is light, the
spool valve of the oil control valve moves to the right (head for the
coil). By this spool valve movement, the pressurized oil is led into
the chambers for timing retarding and the oil in the chambers for
timing advancing is drained. This operations actuate the rotor and
result in the retarded timing of the intake valve.
Targeted timing varying operation
DRIVING
CONDITION
VALVE TIMING TARGET OF CONTROL EFFECT
Engine running at idle
speed Most retarded To shorten the valve opening overlap
in order to prevent the exhaust gas
counterflow to intake manifold. Stabilization of the
engine rotation at idle
speed.
Average engine load
range To the advanced side To lengthen the valve opening over-
lap in order to enhance the internal
exhaust gas recirculation and
reduce the pumping loss. Improvement of the fuel
efficiency.
Lowering of the exhaust
emission.
Light engine load
range To the retarded side To shorten the valve opening overlap
in order to prevent the exhaust gas
counterflow to intake manifold. Keeping of the engine
stability.
Low or average
engine speed range
with heavy engine
load To the advanced side To advance the closing timing of the
intake valve in order to improve the
volumetric efficiency. Improvement of gener-
ating the engine torque
at low and average
engine speed.
High engine speed
range with heavy
engine load To the retarded side To retard the closing timing of the
intake valve in order to improve the
volumetric efficiency. Improvement of gener-
ating the engine power.
Low engine coolant
temperature Most retarded To shorten the valve opening overlap
in order to prevent the exhaust gas
counterflow to intake manifold and
reduce the fuel increasing.
To slow the fast idle speed of the
engine as a result of stabilizing the
engine idling. Stabilization of the fast
idling of the engine.
Improvement of the fuel
efficiency.
At engine starting and
stopping Most retarded To shorten the valve opening overlap
in order to prevent the exhaust gas
counterflow to intake manifold. Improvement of start
ability