System Functional Check
- Warm engine to operating temperature, and let idle at least 2 minutes after warm-up in park/neutral. Disconnect hose at EGR valve and attach a vacuum gauge to the hose.
- Open the throttle quickly several times. A fluctuation of several inches of mercury should be observed during throttle movement. Disconnect vacuum gauge.
- Attach a hand vacuum pump, or other vacuum source to the EGR valve. With engine running apply vacuum to the valve. The engine should drop several hundred RPM, stumble or stall.
- Disconnect the vacuum source and reconnect the normal signal hose to the EGR valve. If the system operated as described, the system is operating correctly, if not, see TROUBLE SHOOTING .