Haltech F10 - Manual (Page 71)

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Fig 14.1. The idle-air circuit.
There should be sufficient airflow around the
closed throttle plates to permit the engine to
idle slowly even with no air passing through
the idle bypass circuit. The throttle stop
should be adjusted to ensure this is the case.
Remember that the throttle position sensor
will need re-calibration if the throttle limits
are altered.
Install the idle air circuit and the stepper motor, and attach the idle speed motor to its
connection on the F10A harness. Run the F10A programming software ONLINE and go to
the Output Options Page. Ignition will need to be switched on.
The idle speed motor is only adjusted when the ECU determines that the engine is in an idle
condition; that is, throttle closed (0%), and engine speed and manifold pressure within limits
(see below).
14.3 Adjusting the Idle Speed Control
There are ten parameters to be adjusted in the idle speed control.
Enable/Disable
The Idle Speed Control can be switched on or off.
Target Idle Speed
This is the engine speed that the ECU attempts to maintain at idle.
Cold Idle-Up RPM
This speed is added to the Target Speed when the engine temperature is cold.
Start RPM
For a period of around 20 seconds after the engine starts, you can specify an extra
increase in idle rpm. M ost factory cars will rev 200-300rpm above the cold idle-up
RPM for a small time when they are first turned on. Setting the Start RPM to 0 will
mean that the engine will rev to the Target Idle Speed + Cold Idle-Up RPM when
turned on and resort back to the Target Idle Speed when warm. If you set the Start
RPM to 200RPM , then the engine will rev to the Target Idle Speed + Cold Idle-Up
RPM + 200RPM and resort back to the Target Idle Speed + Cold Idle-Up RPM after
20 seconds and then resort back to the Target Idle Speed when warm. Graphically, this
can be represented as: