Air By-Pass Circuit
- Disconnect air hoses from ports "A" and "B" of air control valve. Start engine and warm to normal operating temperature. Turn engine off.NOTE: Port "A" is connected to air injection manifold and port "B" is connected to catalytic converter pipe.
- Restart engine and increase engine speed to 1500 RPM. Air should exhaust from port "A" of the air control valve for approximately 30 seconds, then exhaust from port "B".
- If no air exhausts, inspect base of diverter valve for air. If air is being exhausted, increase engine speed to 1500 RPM and determine if vacuum is being applied to diverter valve.
- If vacuum is present, replace diverter valve and retest. If no vacuum is present, test diverter solenoid as outlined in Computerized Emission Control article in this section.
- If air is not being exhausted from base of diverter valve, inspect air pump for proper operation. If air exhaust from air control valve is normal, depress accelerator to floor, return engine to idle and check base of diverter valve for air exhaust. If air is exhausted, circuit is okay.
- If no air is exhausted, check diverter valve vacuum hose for vacuum. If no vacuum is present, replace diverter valve.
- If after replacement of diverter valve, there is still no vacuum present in diverter vacuum hose, test diverter solenoid as outlined in COMPUTERIZED EMISSION CONTROL article.