EGR Valve
- Disconnect vacuum hose to EGR valve. Plug end of disconnected hose. Connect a vacuum pump to EGR valve. With engine idling, apply vacuum to EGR valve. If vacuum holds and idle becomes unstable or engine stalls, EGR valve is functioning properly.
- Ensure engine is at normal operating temperature. Connect a vacuum gauge to EGR hose. Increase engine speed to about 3000 RPM. If vacuum is shown on gauge, system is functioning properly.