Pickup 2WD L4-2254cc 2.3L SOHC (4ZD1) MFI (1994)
Air Regulator: Description and Operation
As a mechanism to raise idle speed during cold, fast idle conditions, the air regulator controls air flow through a hose that bypasses the throttle
valve. The regulator contains a temperature sensitive electric element that causes the air bypass to close gradually as the engine warms up. When
the engine has run for approximately five minutes, the valve should be fully closed.
Air Regulator Operating Graph
The air regulator is energized through the fuel pump relay and not directly controlled by the ECM.