Deceleration Valve
- Remove air cleaner, plug air cleaner vacuum source and connect tachometer to engine. With engine running at idle, remove deceleration valve signal hose from intake manifold.
- Reconnect signal hose and listen for air flow through ventilation pipe and into deceleration valve. Engine speed should drop when hose is reconnected.
- If air flow lasts less than 1 second or engine speed does not drop, check for defective hoses or deceleration valve.