1978 XJ6 Models
Valve is located in carbon canister vent line. Valve prevents engine dieseling after ignition is switched off by closing canister vent and simultaneously allows a slight vacuum to top of carburetor float bowl. This vacuum equals vacuum already present in low mixture needle. When ignition is switched off, voltage is applied to valve solenoid until oil pressure drops to zero at which time oil pressure switch breaks circuit and valve solenoid is de-energized.