Exhaust Gas Recirculation: Testing and Inspection

Fig. 29 EGR valve identification.:

5M-GE ENGINE

1. Inspect filter in EGR vacuum modulator and clean as necessary using compressed air.
2. Connect vacuum gauge in line between EGR valve and vacuum modulator.
3. Start engine and ensure engine runs at idle. If engine runs rough or stalls, check for improperly seated EGR valve.
4. With coolant temperature below 135°F and engine running at 2500 RPM, observe vacuum gauge. If gauge reading is not zero, VSV is defective.
5. Run engine until normal operating temperature is reached and ensure gauge reading is approximately 2.76 inches Hg at 2500 RPM.
6. Disconnect hose from ``R'' port of vacuum modulator and connect port to intake manifold vacuum, Fig. 29. Gauge should indicate high vacuum at 2500 RPM.
7. Remove vacuum gauge and adapter and reconnect hoses, then apply manifold vacuum directly to EGR valve.
8. If engine does not run rough or stall, EGR valve is defective.