1995 Chevrolet Tahoe 1995 Chevrolet C1500 1993 GMC K2500 engine stumbles on acceleration

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Filed Under (Chevrolet) by admin on 10-06-2010

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Customer Concern: The engine stumbles on acceleration and the Exhaust Gas Recirculation (EGR) valve is opening too soon. Tests/Procedures: 1. With the engine off, use a vacuum pump to pump the valve open. It should pump up and hold vacuum. 2. With the valve still pumped up, reach in and crank the engine over, the valve should slam shut and be closed before the engine starts. Potential Causes: Defective Exhaust Gas Recirculation (EGR) Valve Tech Tips: This has a negative back pressure type valve. The back pressure circuit in the valve gets plugged and causes the valve to open too soon. Diagnostic Codes: None