Tuning Definitions - Holley Sniper EFI 550-849 Installation Manual

TUNING DEFINITIONS

Target air fuel ratio
Target air fuel ratio
Target AFR
Target air fuel ratio
together automatically. Consequently, the air/fuel you see on the MONITOR screen,
may not be exactly what you set for the settings. Changing these settings raises or
Acceleration
Enrichment
Fuel prime enable
Fuel Prime
Fuel prime percent
Note: Fuel Prime occurs 2.5 seconds after key-on. If you quickly turn the ignition key
without waiting for the full 2.5 seconds, the prime will not occur and it may take longer
Basic : Basic Fuel
Typically between 13.5 and 15.0. Engines with larger cams may
need a richer setting for smoothest idle.
at idle
Typically between 13.5 and 15.5. Engines with larger cams may
need a richer setting for smoothest operation.
at cruise
Typically between 12.0 and 12.8. Running richer may reduce
power. Running leaner may reduce power or cause potential
at WOT
engine damage
Note: The Target Air/Fuel setting between IDLE, CRUISE, and WOT is blended
lowers the "curve" of that specific area.
Changes the "accelerator pump" function of the fuel injection.
Raising the number increases the amount of fuel added when the
Acceleration pedal is pushed. Lowering the number decreases the amount of
Enrichment fuel added when the pedal is pushed. It is highly recommended
NOT to change this until the ECU is allowed to perform self-
tuning
Fuel prime is an option that is enabled by default in all of the
base calibrations. The fuel prime function injects a small shot of
fuel into the intake manifold 2.5 seconds after the ignition is
turned on (which is also the amount of time it takes the 3.5" touch
screen to power up), wetting the intake and allowing the engine
to start much quicker. The amount of fuel injected is based on
coolant temperature and cranking fuel. This amount of fuel can
be increased or decreased by changing the "Percent" value.
If the engine seems flooded reduce this value, if the engine
seems to want more fuel, increase it. Experiment for best
results. Typically this value will range from 75-150% with a
maximum of 200%.
This value will multiply the "Fuel Prime Percent" at CTS values
Fuel Prime colder than 160°F. It is a linear decay from -40°F to 160°F (i.e. a
Multiplier value of '5' will provide 5 times the prime shot at -40, 2.5 times at
60, and zero change at or above 160).
for the engine to start.
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