NOTE: This procedure applies to STC engines only.

This no-air check must be made on a dynamometer.

Check the fuel pump code AFC no-air fuel (rail) pressure at 1600 rpm.

• The pressure on the engine must be within 48 kPa [7 psi] of the no-air pressure setting on the fuel pump test stand
• The fuel pump test stand no-air values are listed in the Fuel Pump Calibration Values Manual, Bulletin 3379352, under the fuel pump code number.

NOTE: Use line, Part Number ST-435-1, furnished with the gauge.

Install a rail pressure gauge, Part Number ST-435, to the shutoff valve.

Install a tachometer, Part Numbers 3375631 or 3377462.

Remove the AFC air supply line from the air intake manifold or the compressor air tube.

Install a plug or a cap in the intake manifold hole.

Operate the engine in the gear that will produce rated power and or speed.

Remove the air from the fuel and oil pressure gauge lines while the engine is warming to operating temperature.

Fully depress the accelerator or set the fuel pump throttle lever wide open.

Increase the load until the engine is at the specified rpm.

Check the AFC no-air rail pressure.

If the no-air setting is not within the recheck specifications, remove the fuel pump and set the no-air value on a fuel pump calibration stand.