Pulse Air System: Testing
- Disconnect and plug lower air suction hose from anti-afterburn valve. Raise and support front of vehicle. Remove air cleaner cover and filter.
- Start engine and run at idle speed. Check for bubbling noise from air suction port. See Fig 2. If bubbling noise is not heard, proceed to step 5. If bubbling noise is heard, disconnect hose from control switch at air suction cut-off diaphragm.
- Bubbling noise should stop. If bubbling noise is still heard, replace air suction cut-off diaphragm and retest. If bubbling noise stops, check for voltage at control switch solenoid valve (Yellow/Black terminal).
- If there is voltage, replace speed sensor and retest. If no voltage, replace control switch solenoid valve and retest.
- Place shift lever in second position (selector lever in 2 position) and accelerate above 15 MPH. Quickly release throttle and check for bubbling noise. If bubbling noise is heard, test is complete.
Check for bubbling noise.
- If bubbling noise is not heard, disconnect hose from air suction cut-off diaphragm valve and connect vacuum gauge to hose. Again accelerate above 15 MPH and check for vacuum.
- If there is no vacuum, proceed to step 8). If vacuum is present check air suction line from air cleaner to exhaust manifold through air suction valve for leaks or disconnected hose. If suction line is okay, replace air suction valve and retest.
- Remove cover from emission control box on Accord models or box #1 on Civic and Prelude models. Disconnect hose from control switch and check for vacuum during deceleration below 15 MPH. If there is vacuum replace control switch and retest.
- If there is no vacuum, check for voltage at control switch solenoid valve (Yellow/Black terminal). If voltage is present, check vacuum line to intake manifold for leaks, blockage or disconnected hose. If okay, replace control switch solenoid valve and retest.
- If no voltage is present, check wiring and fuse. If okay, replace speed sensor and retest.