System Operational Test

The following procedures will allow a basic operational test of the EGR system. Since the EGR operation is controlled by the ECU, refer to COMPUTERS AND CONTROL SYSTEMS for further information concerning testing of the systems operation.

EGR System Inspection (California Only):

1. Disconnect the green striped vacuum hose from the EGR valve body and connect a hand vacuum pump using a vacuum "Tee".
2. While the engine is cold (coolant temperature less than 60 degrees C or 140 degrees F) race the engine and verify that no vacuum is present.
3. Allow the engine to warm up (coolant temperature greater than 70 degrees C or 158 degrees F) and verify that when the engine is raced vacuum rises momentarily to 14 kPa or 3.9 in. Hg.

EGR Valve Inspection (California Only):

4. Disconnect the vacuum "Tee" and connect the vacuum pump directly to the EGR valve.
5. Apply 26 kPa or 7.5in. Hg while the engine is at idle and verify that idle becomes unstable.