Jaguar AJ-V8 Automobile User Manual


 
EngineAJ-V8/5HP24
26
Valve Timing Solenoid
The valve timing solenoid controls the position of
the shuttle valve in the bush carrier. A plunger on
the solenoid extends when the solenoid is
energised and retracts when the solenoid is de-
energised.
Operation
When the valve timing solenoids are de-
energised, the coil springs in the bush carriers
position the shuttle valves to connect the valve
timing units to drain. In the valve timing units, the
return springs hold the ring pistons and gears in
the retarded position.
When the valve timing solenoids are energised
by the ECM, the solenoid plungers position the
shuttle valves to direct engine oil to the valve
timing units. In the valve timing units, the oil
pressure overcomes the force of the return
springs and moves the gears and ring pistons to
the advanced position.
System response times are 1.0 second maximum
for advancing and 0.7 second maximum for
retarding.
While the valve timing is in the retarded mode,
the ECM produces a periodic lubrication pulse.
VALVE TIMING SOLENOID
VARIABLE VALVE TIMING OPERATION
Retarded
Advanced
Engine Oil Pressure
303-004
Engine Oil Pressure
303-005