Dodge Colt/Challenger/Conquest/Vista 1971-1989 Repair Guide

Manual Altitude Compensation System



This system is used on 1977 and later models.

An off-on valve is used to increase the air supply to the carburetor to lean the mixture and decrease the EGR flow for high altitude operation.


The required maintenance is to inspect any vacuum hoses and routing for kinks, breakage and cracks. The off-on valve should be on for high altitude and off for driving under 4,000 ft.