Isuzu Cars and Trucks 1981-1991

Air Injection Reactor System

Print

OPERATION

The air injection reactor system is used on RWD I-Mark, 1986 and 1990 Amigo, Pick-Up and Trooper.

In gasoline engine, it is difficult to burn the air-fuel mixture completely through combustion that takes place with the combustion chambers. In order to reduce HC and CO emissions, the system draws air into the exhaust ports to speed up oxidation. The air management valve switches air passage from the air pump through a vacuum management valve which is actuated by an electric signal supplied from the ECM.

The air pump is belt driven by the pulley mounted on the water pump shaft of the engine. Air is drawn through the air cleaner and suction hose into the outlet chamber, where it is trapped between two vanes and the pump body. As the rotor turns, these vanes carry the air to the outlet chamber and then to the air manifold.



Click image to see an enlarged view

Fig. Air injection reaction system RWD I-Mark (G180Z engine)

SERVICE

G180Z and G200Z Inspection: The check valve should only allow air to flow in one direction. If air does not flow or in both directions, the valve is defective and must be replaced.

The air switching valve is designed to switch air flow from the air pump. When the manifold vacuum flows to the pipe, the air switching valve allows air from the pump to flow to the check valve.

4ZE1 engine: With the engine at normal operating temperature and at idle, disconnect the vacuum signal hose (Y) from the VSV and vacuum hose (X and Z) from the ASV. Disconnect the air hose 1 at the check valve and plug the valve. Connect the vacuum signal hose (Y) directly to the pipe A of the ASV. Secondary air should continue to blow out from pipe B of the ASV. If a problem is found, replace the ASV (air switching valve).

4XE1 DOHC and 2.8L V6 engine: Refer to the diagnostic chart in this section.



Click image to see an enlarged view

Fig. AIR system check valve



Click image to see an enlarged view

Fig. AIR switching valve



Click image to see an enlarged view

Fig. Air Injection Reaction (AIR) system 4ZE1 engines



Click image to see an enlarged view

Fig. Air injection system 4XE1 DOHC engine



Click image to see an enlarged view

Fig. Air injection diagnosis chart 4XE1 engine

 
label.common.footer.alt.autozoneLogo