Holley 550-407, Installation Manual, Page: 29 / 54

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24.0 STARTUP
The vehicle should be ready to be started. Open the sensors screen. Make sure the TPS is reading 0. If it does not, do a TPS
AUTOSET, or if it is reading 1-2%, close the idle screw on the throttle body slightly.
Crank the engine and look at the RPM parameter. It should change to “Syncng”, indicating the ECU is syncing with the RPM signal for an
instant, then show an RPM signal. The engine should fire and run and come to an idle.
If you do not get an RPM signal, there is an error in the wiring or system setup. Call Holley Tech service for advice.
If the engine starts but is idling too low and appears to be struggling for air, you may have to open the throttle body idle speed screw at
this time. If you move the screw, you will need to perform a TPS Autoset.
25.0 SETTING IGNITION TIMING
If you are using a computer controlled GM HEI or Ford TFI distributor, you must sync up the ignition timing with the ECU. You must have
a timing light to perform this. You will possibly need a dial-back timing light or a harmonic balancer that is degreed up to 40 degrees.
Again, open the Sensors monitor screen.
You will see the “Ign Timing” parameter which will display what the commanded ignition timing
is. Rev the engine up (CAREFULLY) to approximately 2000 RPM. Note the timing value on the handheld. Using the timing light, turn the
distributor until the timing you see with the timing light matches what is on the handheld. Once synced, tighten down the distributor. From
this point on, do not turn the distributor. The timing on the handheld should always match the timing on the distributor.
IMPORTANT NOTE: The timing at idle (TPS = 0) might be seen to be rapidly fluctuating. This is due to the ECU using the ignition timing
to stabilize the idle. This is normal. This is why you need to check and sync the timing around 2000 RPM.
26.0 AFTER-STARTUP
Once the vehicle has started, look for any fuel or coolant leaks. Let the vehicle warm up and look at some other parameters to make
everything is operating properly. Go into the MONITOR, MONITORS,
and select the “Closed Loop” Icon.

Closed Loop Status
–
Indicates whether the
engine is “Closed Loop” or “Open Loop”. Closed Loop indicates that the ECU is
adding or subtracting fuel to maintain the target air/fuel ratio. The
TERMINATOR™ calibrations are such that the system should
be operating closed loop almost all of the time.

Closed Loop Compensation
–
This is the percentage of fuel that the ECU is adding or subtracting to maintain the target air/fuel
ratio at any specific moment. A value with a minus (-) sign in front indicates the ECU is removing fuel. A value with no minus
sign indicates the ECU is adding fuel. When in open loop operation, this will always stay at 0%.

Target Air/Fuel Ratio
–
This is the target AFR (air/fuel ratio) the ECU is trying to maintain. This will vary depending on the
engine speed and load.

Air/Fuel Ratio Left
–
This will show the air/fuel ratio the wideband oxygen sensor is reading. The Closed Loop Compensation
should be adding or subtracting fuel all the time such that the AFR Left should always be close to the Target AFR value. (Note
ARF Right will only be active if a second sensor is being used which is not included).

Fuel Learn Status
–
This indicates the status of the
TERMINATOR™ “Self Tuning” operation (Learn Status). The system will
automatically tune itself as you drive around. There are several conditions that must occur in order for the Self Tuning to occur.
The engine temperature must exceed 160° F. The system must be operating in a closed loop mode, and the Self Tuning must be
enabled. The base
TERMINATOR™ setups have the Self Tuning enabled. Once the engine reaches 160° F, the Self Tuning
should be active
. The Learn Stat will show “NoLearn” when Self Tuning is not active and “Learn” if Self-tuning is active.
If any of these parameters are not showing a proper value, find out why before further driving the vehicle.
27.0 IDLE SETTING/THROTTLE PLATE SETTING
Once the engine is up to operating temperature, the idle speed can be set to what is desired.
From the HOME SCREEN, select the TUNING tab. Then select the BASIC and then BASIC IDLE. You can see what the target hot idle
speed is set to. If you are happy with the current value, use the BACK or HOME button to exit. If you would like to change it, click on the
IDLE SPEED. This brings up a screen to adjust the idle speed. Move the button left and right to adjust it. Click the button to save the
new value or select CANCEL at the bottom to move out of this screen.