Quick Fuel Technology Qfi Electronic Fuel Injection System - Manual (Page 2)

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Glossary of terms
Below are terms that are frequently used in this installation/instruction manual.
ADAPTIVE LEARNING - This feature utilizes the wide band oxygen sensor in the exhaust downpipe to determine
the engine’s real-time air/fuel (A/F) ratio. The Engine Control Unit (ECU) will instantly make the necessary fuel
input changes to keep the engine on the desired air/fuel ratio, all the time, and under all conditions. In short, the
“Adaptive Learning” feature is constantly making minor adjustments to maintain the optimum relationship
between the fuel and air fed into the engine, allowing it to operate at its highest efficiency for power and/or fuel
economy. At the initial start-up, the engine uses the Targeted Air/Fuel Ratio (see below for more details) to
control the engine.
CLOSED LOOP - “Closed loop” is the default setting for the ECU, making the "Adaptive Learning" feature functional.
To shut off "Adaptive Learning,” the "Closed Loop" feature must be cancelled.
DASHBOARD - This is the laptop software that is on the supplied disc. This provides you with the ability to infinitely
tailor your system. It also contains features for advanced tuners.
DATA LOGGING - The Qfi software package can record a wide range of data while driving the vehicle. This allows
you to see a timeline of what has occurred during vehicle operation. This feature requires a laptop (not a Mac) to
be connected use this function.
ECU - Engine Control Unit. This is the small computer that controls the flow of fuel from the throttle body to the
engine.
kPa - The abbreviation for kilopascals, the metric term used to measure vacuum and pressure. You are probably
used to seeing "inches of vacuum" and "pounds per square inch" of pressure. Kilopascals are used because the
measure terms for vacuum and pressure are the same. The range of 0-100 kPa covers the vacuum part of the scale
while 100 and up is the pressure portion of the scale. In other words, a reading of 100 kPa is zero inches of
vacuum and zero PSI. The handheld controller software show the kPa reading as the dominant number, but below
that, is the conversion to either inches Vacuum or PSI pressure.
MAP - This term describes two different things. For more clarity, we use the lower case for “map” to refer to the
program which details or “maps” the engine functions. Upper case "MAP" refers to the term Manifold Absolute
Pressure (measured in kPa).
MAP SENSOR - The MAP Sensor provides instantaneous manifold pressure information (in kPa) to the ECU. This is
used to calculate the air density, in turn determining the engine's air mass flow rate. This controls, through the
ECU, the required fuel metering for optimum combustion.
PULSE WIDTH - Pulse Width refers to the length of time, measured in milliseconds (1/1000 or 0.001 second), the
injector nozzle is open and injecting fuel into the airstream. It is controlled by the ECU mounted on the QFI
throttle body. While this setting can be changed, it normally is left alone. The “Adaptive Learning” feature controls
the pulse width to control the optimum A/F ratio.
SET UP MENU - This is the part of the Dashboard software that allows you to customize the base map for your
specific engine. This includes the Volumetric Efficiency (VE) tables.
TARGETED AIR/FUEL RATIO - This is the initial map installed on the computer after answering the set up questions
on the hand held controller. This establishes what the computer believes is the ideal air/fuel ratio for the best
performance. The "Adaptive Learning" feature of the QFI system modifies the real-time Air/Fuel Ratio (A/F) as the
vehicle is driven. This A/F ratio may change at various RPMs or driving conditions. This is a distinct advantage over
the carburetor or an EFI system which attempt to run a fixed A/F ratio all of the time.
Volumetric Efficiency (VE) - This refers to the efficiency with which the engine can move the fuel/air charge into
and out of the cylinders.