Air Injection Pump: Testing and Inspection

EXCESSIVE BELT NOISE
1. Check for loose drive belt or seized air injection pump.

EXCESSIVE PUMP NOISE
1. Inspect hoses for leaks and check that all connections are tight.
2. Check hoses for proper routing.
3. Check pump mounting bolts for looseness.
4. Verify proper operation of injection pump, check valve, switch/relief valve and diverter valve. A new air pump may emit a ``chirping'' noise. This noise should go away after a break-in period of approximately 1000 miles.

NO AIR SUPPLY
1. Accelerate engine to 1500 RPM and observe air flow from hoses.
2. If air flow increases as engine speed increases, the pump is functioning normally. If not, proceed as follows:
a. Check tension of drive belt.
b. Inspect supply hose, fittings and diverter valve for air leaks.
c. Verify proper operation of check valve and diverter valve.