Test Procedure

To eliminate or confirm engine smog reduction system as a source of engine loping or rough idle complaints, proceed as follows: Disconnect regulator valve at intake manifold side of the ventilation tube. Attach service valve tool to connection which leads to intake manifold. Leave opposite end of valve vented to the atmosphere, Start the engine and observe idle in comparison to the prior idle condition. If loping or rough condition remains with regulator valve tool installed smog reduction system is not at fault. Further engine diagnosis and repair will have to be conducted to find the fault. If idle condition is satisfactory, proceed with the servicing of the system as outlined under "SERVICE PROCEDURES".