Exhaust Gas Recirculation: Testing and Inspection

INSPECTION

1. Run engine until operating temperature is reached.
2. Disconnect exhaust gas recirculation vacuum line from exhaust gas recirculation valve.
3. Ensure there is no vacuum from hose at idle, then raise engine speed to 2500-3000 RPM, low vacuum should exist.
4. Stop engine, then connect hand held vacuum pump or apply manifold vacuum directly to exhaust gas recirculation valve.
5. With engine idling apply vacuum and observe exhaust gas recirculation diaphragm movement. The diaphragm should move freely up and down. As exhaust gas recirculation valve opens, engine should run rough or stall.
6. Reconnect vacuum feed line. If exhaust gas recirculation valve does not operate as specified, check vacuum lines for kinks or physical damage.
7. If vacuum lines are satisfactory, replace exhaust gas recirculation valve.