|
|
etc., (if applicable) are not by-passed or modified. Ensure vacuum hose(s) to EGR valve is not plugged.
Fig. 11: Typical Single Diaphragm EGR Valve
Courtesy of GENERAL MOTORS CORP. Dual Diaphragm EGR Valve This type uses 2 diaphragms with different effective areas and 2 vacuum sources. Although similar to the single diaphragm type, the second Fig. 13 . These diaphragms form a vacuum chamber which is connected to manifold vacuum. During highway cruising when manifold vacuum is high in the center chamber, manifold vacuum tends to pull the valve closed. However, the When manifold vacuum is low during acceleration, the higher vacuum signal opens the valve, permitting more EGR. When manifold vacuum is Verify EGR valve is present and not modified or purposely damaged. Ensure thermal vacuum switches, pressure transducers, speed switches,
Fig. 12: Typical Dual Diaphragm EGR Valve
Courtesy of GENERAL MOTORS CORP. Positive Backpressure EGR (BP/EGR) Valve |