Exhaust Gas Recirculation: Testing and Inspection

NOTE: Before inspection, check to make sure that gear shift lever is in neutral position (with A/T model, selector lever in "P" range) and that parking brake lever is pulled all the way up.





1. When engine is cool (coolant temperature is below 40°C, 104°F), start engine and race it (higher than about 3,500 r/min), and check that EGR valve diaphragm is not operating in this state.

CAUTION: If EGR valve is hot, it may be necessary to wear gloves to avoid burning fingers.






2. Warm up engine to normal operating temperature and race it after warming up. Then check to be sure that diaphragm moves toward 1 in the figure during acceleration and toward 2 during deceleration. If EGR valve fails to operate properly, check vacuum hoses, EGR valve, EGR pressure transducer and EGR solenoid vacuum valve.
3. Keep engine running at idle speed and open EGR valve by hand, and engine should either stop or reduce its speed. If neither occurs, EGR passage is clogged. Clean it.