DESCRIPTION
The air suction system uses exhaust gas pulses to draw air into the catalytic converter which helps to complete oxidation of emissions. This system includes an air suction (AS) valve, an air suction filter (Federal RWD Corolla and all Tercels), and hoses.
California vehicles also use a vacuum transmitting valve (VTV) and shutoff valve.
OPERATION
Air is drawn through the filter and air suction (AS) valve into exhaust manifold on California vehicles. Air is drawn through the filter and air suction (AS) valve into catalytic converter on Federal vehicles.
AIR SUCTION (AS) VALVE
- To check AS valve on Federal models, blow and suck on pipe. On auto. trans. Tercel sedan and 4WD wagon, check that no air passes when sucked from filter side, but air passes when blown hard. On all other Federal models, check that no air passes when blown hard from converter side, but air passes when sucked. If not, replace valve.
- To check AS valve on California models, apply vacuum to shutoff valve and blow into port. Check that air flows from filter side to outlet port. Check that air does not flow from outlet port to filter side. Release vacuum. Check that hardly any air flows from filter side to outlet port. If not, replace valve.
VACUUM TRANSMITTING VALVE (VTV) (CALIFORNIA VEHICLES)
Check VTV by blowing air into each side. Check that air flows without resistance from side B to side A. Check that air flows with difficulty from side A to side B. If problem is found, replace valve.
SYSTEM TESTING
- Check condition of all hoses and tubes. On Federal models, disconnect air suction hose from air cleaner. Start engine. With engine idling, check that air is drawn into inlet pipe.
- On California models, disconnect vacuum hose from shutoff valve and plug hose end. Remove air cleaner cap and start engine. Reconnect vacuum hose to shutoff valve. Check that bubbling noise is heard from AS valve inlet within 2-6 seconds. Reinstall the air cleaner cap. If system does not operate as outlined, check each component. See COMPONENT TESTS.