DIESEL LOW POWER BLACK SMOKE OPERATION OF EPR VALVE. Pontiac Parisienne (Canada) 1981

For 1990-2009 cars

# DIESEL LOW POWER BLACK SMOKE OPERATION OF EPR VALVE

WHEN INVESTIGATING A CONDITION OF BLACK SMOKE AND LOW POWER, CHECK FOR THE PROPER OPERATION OF THE EXHAUST PRESSURE REGULATOR (EPR) VALVE. THE VALVE IS CLOSED AT IDLE TO INCREASE EXHAUST PRESSURE WHICH INCREASES EGR FLOW TO THE ENGINE. THE EPR VALVE OPENS ABOVE IDLE TO ACHIEVE A NORMAL EGR LEVEL FOR TYPICAL DRIVING. DIESEL ENGINE EXCESSIVE SMOKE AND LOW POWER: A MALFUNCTIONING EPR SYSTEM CAN CAUSE BLACK SMOKE AND LOW POWER. CHECK TO SEE IF THE EPR VALVE IS OPERATING PROPERLY BY FLASHING THE THROTTLE AND OBSERVE THE EPR SHAFT TO SEE IF THERE IS MOVEMENT. IF THERE IS NO MOVEMENT, IT INDICATES A SYSTEM MALFUNCTION. REFER TO THE DIAGNOSTIC SECTION OF THE SERVICE MANUAL, SECTION 6A5.

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