Holley 550-407, Installation Manual, Page: 30 / 54

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Figure 52
Whether you change the target idle or not, you need to set the throttle plates on the throttle body to an optimal position. To do so, with the
engine running select the MONITOR tab. You will see the IDLE screen. Look at the “IAC Position” value. This value should be set
between 2 and 10 with the engine in neutral and up to operating temperature
. Also make sure the “TPS” value is showing a value of 0. If
it is not, you need to perform a TPS AUTOSET.
If the “IAC Position” value is showing zero, you must close the throttle plates until it reads a value of 2-10. Slowly turn the throttle shaft
adjustment screw on the throttle body out (counter-
clockwise). If the IAC position is “stuck” at 0, it is likely that the engine is idling at a
higher speed than you have set the target idle speed for. You need to adjust the throttle plates to resolve this issue.
If the “IAC Position” value is greater than 10, it is a good idea to open (turn the throttle shaft adjustment screw in, clockwise) the throttle
plates until the “IAC Position” value is between 2 and 10. Note that if you open the throttle plates such that the “TPS” position goes above
a value of 0, you will need to shut the vehicle off and perform a TPS AUTOSET. Then restart the vehicle and continue adjusting the
throttle plates. Once the TPS goes above a value of 0, the ECU goes out of its “idle” mode and will lock the IAC Position to a fixed value.
When the adjustments are completed, make sure the TPS reads a value of 0 with the engine idling.
28.0 SELF-TUNING
At this point, it is time to just drive the vehicle and let the system perform its self-tuning process. The best way for this is to drive the
vehicle under as many different operating conditions as possible. Different engine speeds and loads. Start by slowly revvin g the engine
up in neutral and holding it at different speeds up to 2500 RPM. This will help the system learn these points. Then drive the vehicle,
possibly using different transmission gears to learn in different areas. If you have an automatic transmission you may want to put it in
gear, and with your foot on the brake pedal, apply a SMALL amount of throttle so that the system learns in this area as well.
NOTE: There are several conditions where Learning will NOT occur. They are the following:

If the engine is below 160° F

When the engine sees quick accelerator pedal movement

Certain times when the accelerator pedal is lifted and the vehicle is coasting

If the learn is disabled by the user
If you are interested in seeing if Self Tuning is completed in a certain area, you can look at the following:

Select MONITORS from the HOME SCREEN

Select the LEARN icon

The FUEL LEARN STATUS indicates if the learn feature is active. The FUEL LEARN PERCENT indicates what the learn value
is.

Look at the CLOSED LOOP COMPENSATION value. Once this value is close to zero, learning is complete in an area.
At this point you can drive and enjoy your
TERMINATOR™ EFI as it is. Sections 28.0 – 32.0 describe how you can adjust
various parameters to further optimize fuel economy and overall performance, if desired.