Impreza Coupe FWD F4-1820cc 1.8L SOHC (1995)
Air Suction Valve: Testing and Inspection
Air Suction Valve
NOTE: If the silencer is melted or black dust is found within the air cleaner, there is a strong possibility the ASV is bad.
1.
Apply vacuum to fitting 3. If vacuum does not hold, replace air suction valve (ASV).
2.
With vacuum applied to fitting 3, blow air into fitting 4. Air should pass. If air does not pass, replace air suction valve.
3.
Start the engine.
4.
Apply vacuum to fitting 3. Exhaust sound should be heard from fitting 4. If noise is not heard, check exhaust passage for restriction.
5.
Release vacuum from fitting 3. Exhaust noise should not be heard. Replace ASV if noise is heard.