Exhaust Gas Recirculation (EGR) System

Fig. 73 Testing EGR system:

1. Disconnect the vacuum hose (green stripe) from the mixing body and connect a hand vacuum pump to the vacuum hose, Fig. 73.
2. Verify that when the engine is cold (engine coolant temperature less than 50 degrees C or 122 degrees F) and running at idle vacuum leaks from the EGR control solenoid valve.
3. Warm up the engine (coolant temperature greater than 85 degrees C or 185 degrees F) and verify that when 8 kPa (3 in. Hg) vacuum is applied that vacuum holds.
4. Apply 23 kPa (7 in. Hg) of vacuum and verify that the idle becomes unstable or the engine stalls.