N14 Base Engine Troubleshooting and Repair Manual – 006-047   AFC No Air Check

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 No.

  3379352, under the fuel pump code number.

NOTE: Use line, Part No. ST-435-1, furnished with the gauge.

Install a rail pressure gauge, Part No. ST-435, to the shutoff valve.

Install a tachometer, Part No. 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.