Test 4: Closed Loop Operational Test
CAUTION:
Safety shield must be in place at top of carburetor air cleaner.
- Start and warm engine until coolant temperature has stabilized. Remove air cleaner and increase engine speed to 2000 RPM and maintain while observing carburetor stepper motor metering pins.
- Metering pins should step to full rich or full lean position. If they have, go to TEST 6 . If not, check to see if metering pins oscillate around a fixed point. If not, proceed to TEST 9 . If yes, check to see if pins are near full rich or lean position. If yes, perform TEST 6. If not, pins should be oscillating near mid point. Closed loop circuit is functioning normally and test is complete.