Exhaust Gas Recirculation: Testing and Inspection

1. Hoist vehicle so that rear wheels rotate freely.
2. Set M/T or A/T in "Neutral" and transfer in "2H".





3. Start engine, release parking brake lever and check that rear propeller shaft (tires) is turning.
If not, perform following check with one rear tire locked and the other turned by hand.

WARNING:
Make sure that M/T or A/T is set to "Neutral" position for this check. If it is set to any other position, rear tires will turn at high speed and a very dangerous situation may occur.





4. When engine is cool (coolant temperature is below 55°C, 131 °F), race engine and check that EGR valve diaphragm is not operating in this state, by touching diaphragm with finger.

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





5. Warm up engine to normal operating temperature and race it after warming up. Then check to be sure that diaphragm moves toward I in figure at the left during acceleration and toward 2 during deceleration.
If EGR valve fails to operate properly, check vacuum hoses, EGR valve, EGR modulator, EGR SV valve, wire harness and ECM.
6. 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.