EGR Valve: Testing and Inspection

PROCEDURE
1. Start and run engine until normal operating temperature is attained.
2. Place finger on Exhaust Gas Recirculation (EGR) valve diaphragm and accelerate engine; diaphragm should move.
3. Disconnect vacuum hose from EGR valve.
4. Apply 27 kPa (8 in Hg) of vacuum using a vacuum pump to valve with finger on diaphragm. It should move and engine may stall.
5. Check for carbon in valve which may cause restriction. Restriction may be small enough so that engine may stall during Step 4, but large enough to cause a Diagnostic Trouble Code to set. If valve passes the above test, check the EGR pressure transducer. If valve fails, replace the valve.