N14 Base Engine Troubleshooting and Repair Manual – 005-029   Fuel Pump Idle Speed

To check the engine speed, use digital tachometer kit, Part No. 3375631, or optical tachometer, Part No. 3377462.

The remote starter, Part No. 3376506, can be used to start the engine. The leads are marked for their connection points.

NOTE: The idle speed can vary on some applications.

Refer to the fuel pump code for the specified engine idle speed.

Adjust the engine low idle speed between 600 and 800 rpm.

NOTE: This adjustment is sometimes necessary on a new engine to compensate for the added engine driven accessories that are installed by the truck or vehicle manufacturer.

Shut off the engine.

Remove the plug from the spring pack cover.

Install the fuel pump idle adjusting tool into the plug hole. Use tool, Part No. 3375981, for holes with pipe threads and tool, Part No. 3823480, for holes with straight threads.

Operate the engine for 30 seconds at high idle to remove the air from the fuel system.

NOTE: Make sure the engine is at or above 70°C [160°F].

Adjust the idle speed. Turn the tool

clockwise to increase the idle speed and

counterclockwise to decrease the idle speed.

Shut off the engine.

Remove the tool and install the plug.

Operate the engine until the rpm is constant and all of the air is out of the fuel system.

Check the idle speed again.