High Altitude Emission Control System - Non Turbo Only

High Altitude Emission Control System:

The high altitude emission system is used to correct the air/fuel mixture for lower density air at higher than specified elevations. The system consists of an altitude sensing switch, a high altitude solenoid valve, an "idle up" solenoid, and metering jets built into the carburetor. At higher then specified altitudes, the altitude switch closes, energizing the two solenoids. The high altitude solenoid valve opens, allowing filtered air from the air cleaner into the idle and off idle metering systems as well as the primary and secondary main metering systems in the carburetor. The idle up solenoid opens supplying additional air/fuel mixtures to correct and stabilize idle speed.

Altitude Sensing Switch:

ALTITUDE SWITCH

The altitude sensing switch consists of a bellows, and a micro switch. The bellows expands and contracts in response to changes in atmospheric pressure. When ambient air is below a specified pressure (high altitude), the bellows expands, depressing the micro switch which turns the system "on".

High Altitude Solenoid Valve:

HIGH ALTITUDE SOLENOID VALVE

The high altitude solenoid valve opens, when energized by the altitude switch, to supply filtered air from the air cleaner to the altitude compensating passages in the carburetor.

Idle Up Solenoid:

IDLE UP SOLENOID VALVE

The idle up solenoid, installed in the carburetor, is energized by the altitude switch. When energized (at high altitude), the solenoid opens a passage supplying additional air and fuel to the engine to increase and stabilize idle speed.