EGR System Inspection
- Using a 3-way "T" vacuum connector, install a vacuum gauge in hose between EGR valve and EGR vacuum modulator. See Fig 1 . Start engine and ensure engine idles properly. If engine fails to idle, check EGR valve and ensure EGR valve is fully seated.
- To determine if vacuum switching valve is properly controlling vacuum supply, operate engine with coolant temperature less than 102°F (39°C). Vacuum should NOT be present.
- Warm engine to normal operating temperature. High vacuum should be indicated with engine at 3000 RPM.
- To check EGR valve, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If engine does not run rough or stall, check EGR valve.