Lumina V6-191 3.1L VIN T MFI (1993)
Air Injection Pump: Testing and Inspection
Secondary Air Injection Components
OPERATIONAL CHECKS
NOTE: The air pump is a positive displacement vane type which is permanently lubricated and requires no periodic maintenance.
1. Accelerate engine to approximately 1500 RPMs and observe air flow from hose(s). If air flow increases as engine is accelerated, pump is operating
satisfactorily. If air flow does not increase or is not present, proceed as follows:
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Inspect for proper drive belt tension.
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Inspect for a leaky pressure relief valve. Air may be heard leaking with the pump running.
NOTE: If the engine or underhood compartment is to be cleaned with steam or high- pressure detergent, the centrifugal filter fan should be
masked off to prevent liquids from entering the pump.
2. The secondary air injection system is not completely noiseless. Under normal conditions, noise rises in pitch as engine speed increases. To
determine if excessive noise is the fault of the secondary air injection system, operate the engine with the pump drive belt removed. If excessive
noise does not exist with the belt removed proceed as follows:
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Inspect for a seized pump.
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Inspect hoses, tubes and all connections for leaks and proper routing.
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Inspect for air flow from control/bypass valve.
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Inspect pump for proper mounting and bolt torque.
3. If no irregularities exist and the secondary air injection pump noise is still excessive, remove and replace pump.
