Chevrolet Nova/ChevyII 1962-1979

1962-67 Vehicles Without Air


Adjustments should be performed with the air cleaner removed and, on models so equipped, with the air conditioning turned off.

  1. Remove the air cleaner.
  3. Connect a tachometer and vacuum gauge to the engine, set the parking brake, and place the transmission in neutral.
  5. Turn in the idle mixture screws until they seat gently, then back them out 1 1 / 2 turns.
  7. Start the engine and allow it to reach normal operating temperature. Make sure that the choke is fully open, then adjust the idle speed (automatic in Drive, manual in neutral).
  9. Adjust the idle mixture screw(s) to obtain the highest steady vacuum at the specified idle speed, except for the Rochester BV. For this carburetor, adjust the idle mixture screw out 1 / 4 turn from the lean "drop off," the point where a 20-30 rpm drop is achieved by leaning the mixture.

On carburetors having a hot idle compensator valve (air-conditioned models), hold the brass valve down with a pencil while making the mixture adjustment.

  1. Repeat steps four and five if necessary.
  3. Turn off the engine, remove the gauges, and install the air cleaner.