Holley EFI

Idle Setting / IAC Position

Just like a carburetor the throttle plates need to be set to an optimal position; however, the ECU maintains idle speed with an idle air control valve (IAC) in the throttle body.

With the engine running, tap [Monitor] then [Idle]. Look at the “IAC Position” value. This value should be between 2 and 10 with the engine in neutral and up to operating temperature.

If the “IAC Position” value is showing zero, you must close the throttle plates. Slowly turn the throttle shaft adjustment screw on the throttle body out (counter-clockwise).

If the “IAC Position” value is greater than 10, you must open the throttle plates. Slowly turn the throttle shaft adjustment screw on the throttle body in (clockwise).

Note that when you open the throttle plates the “TPS” position may go above a value of 0%. If it does, you will need to shut the engine off and perform a TPS Autoset then restart the engine and continue adjusting the throttle plates.

When the adjustments are completed, make sure the “IAC Position” is between 2 and 10 and “TPS” reads a value of 0%.

TPS Autoset

A TPS Autoset programs the ECU with the full-travel voltage range from idle to wide open throttle for the Throttle Position Sensor (TPS). This must be done with the vehicle ignition power on. The TPS Autoset function is found under [Wizards] from the HOME SCREEN. Select [TPS Autoset] and follow the prompts:

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