CONTROL SYSTEM [13B-MSP]
01-40–13
01-40
2009 Mazda RX-8 Service Highlights (3452–1U–08C)
Revised 11/2008 (Ref. No. R321/08)
End Of Sie
SEQUENTIAL DYNAMIC AIR INTAKE SYSTEM (S-DAIS) CONTROL OPERATION [13B-MSP]
id0140g1304200
Operation Outline
x Operates the SSV solenoid valve, the APV motor, the VFAD solenoid valve (with VFAD), and the VDI solenoid
valve according to the engine speed range.
Operation list
Engine speed range and operation conditions for each valve
On: Energization, Off: Non-energization, Open: Valve opens, Closed: Valve closes
Operation
SSV solenoid valve
x Turns on at the same time as the injection timing of the secondary injector. Due to this, the intake manifold
vacuum is fed to the SSV actuator allowing intake air from secondary port which is opened by the SSV valve.
VFAD solenoid valve (with VFAD)
x At an
engine speed of less than 5,250 rpm, the VFAD solenoid valve turns off and feeds intake manifold
vacuum to the actuator (valve closes).
x At an engine speed of 5,250 rpm or more, the VFAD solenoid valve turns on and feeds BARO to the actuator
(valve opens).
APV motor
x When the following conditions are met, a duty signal is sent to the APV motor, the APV gradually opens. If an
APV-open condition is not met, a minus duty signal is sent to the APV motor, reversing the motor and closing
the APV.
APV-open condition
— Engine speed: 6,250 rpm or more
— ECT: Approx. 70 qC {158 qF} or more
VDI solenoid valve (13B-MSP (high power))
x At an engine speed of 7,650 rpm or more, the VDI solenoid valve turns off and feeds intake manifold vacuum to
the actuator (valve opens).
End Of Sie
FUEL INJECTION CONTROL OUTLINE [13B-MSP]
id0140g1101700
x The fuel injection control includes the following:
— synchronized injection control, which performs fuel injection at the rotor intake stroke according to
designated timing.
— non-synchronized injection control, which performs fuel injection only when fuel injection conditions are met
regardless of rotor intake stroke.
— Fuel cut control, which temporarily stops fuel injection.
x There are primary, secondary fuel injectors, and the injection timing and injection amount va
ries according to
the engine speed range. Due to this, the optimum amount of fuel injection is controlled at all ranges.
End Of Sie
Item
Engine speed range
Low speed Medium speed Medium-high speed High speed
SSV
Solenoid valve OFF ON (Secondary injector is operating)
Valve Closed Open
VFAD
Solenoid valve OFF ON (Approx. 5,250 rpm or more)
Valve Closed Open
APV
Motor OFF ON (Approx. 6,250 rpm or more)
Valve Closed Open
VDI
Solenoid valve OFF ON
Valve Closed Open
To Next Page
