Variable Induction Control Valve: Testing and Inspection
SYSTEM OPERATIONAL CHECKShutter Valve Assembly:
1. Remove shutter valve actuator cover.
2. Start engine and run at idle.
3. Verify that actuator rod is extended at idle.
4. Verify that rod is pulled in when engine speed is increased.
If OK, system is functioning properly. If not, continue testing.
ACTUATOR AND SHUTTER VALVE
1. Disconnect vacuum hose from actuator, and connect vacuum pump.
2. Apply approx. 15" Hg (380mm Hg) vacuum to actuator and hold, while observing vacuum gauge.
^ Actuator rod should retract and actuator should hold vacuum. If actuator does not hold vacuum, replace it. If valve does not move, remove actuator and manually check shutter valve for sticking. Repair or replace as necessary.
VACUUM SIGNAL
1. Disconnect vacuum hose from bottom of solenoid valve, and connect to vacuum gauge.
2. Start engine and observe gauge reading.
^ Should have no vacuum at idle.
If vacuum is present, check solenoid valve operation.
2. Increase engine speed and note vacuum reading on gauge.
^ Should have vacuum beginning at approx. 3,700 rpm.
If not, check vacuum hose routing, vacuum chamber and check valve, and solenoid operation.
VACUUM CHAMBER AND CHECK VALVE
Vacuum Chamber And Check Valve (VRIS):
1. Disconnect hoses from vacuum chamber.
2. Plug one port and connect vacuum pump to the other.
3. Apply at least 10" Hg (254mm Hg) vacuum and hold.
^ Chamber should hold vacuum without leaking down.
If not, replace vacuum chamber.
4. Remove check valve.
Checking Vacuum Check Valve:
5. Blow through check valve and verify that valve passes air in one direction only.
6. If air passes both ways, replace check valve.
7. Install check valve with arrow towards vacuum source.
SOLENOID VALVE CHECK
1. Disconnect hoses from solenoid valve and remove valve.
Solenoid Valve -- No Voltage Applied:
2. Blow through valve from port "B".
^ Air should flow through valve from "B" to the filtered vent.
Solenoid Valve -- Voltage Applied:
3. Apply battery power and ground to the solenoid, and blow through valve again from port "B".
^ Air should flow through valve from "B" to "A", and vent should be closed.
If solenoid valve does not operate as described, replace it.
CONTROL SIGNAL (SOLENOID VALVE)
1. Connect a voltmeter to solenoid valve terminal "B", with solenoid connected.
2. Voltmeter readings should be as follows:
Below 3,700 rpm--approx. 12V
3,700 to 5,750 rpm--below 2.0V
Above 5,700 rpm--approx. 12V
If voltage is not as specified, check related wiring for open or shorts to ground.
If voltage remains constant 12V between 3,700 and 5,700 rpm, either there is an open circuit between solenoid and ECU terminal 2O (that's 2-oh, not twenty), or one or more of the following conditions exist.
a. Faulty throttle sensor or wiring.
b. No engine speed signal to the ECU.
c. ECU not completing circuit to ground (faulty ECU).