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Page 43/55 UltraGauge™ EM User Manual www.ultra-gauge.com
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MENU
UltraGauge Setup ..
Injector Cutoff
Often the engine is used to de-accelerate the vehicle, for example when heading down hill in gear or when the engine is used to
slow the vehicle during engine braking. While in gear and during de-acceleration, many vehicle manufacturers will turn off the
fuel injectors in order to save fuel. This is true for vehicles with either manual or automatic transmissions. The fuel savings is
slight, but over time and distance could become significant. UltraGauge can detect when the injectors are switched off and
factor the fuel savings into the fuel usage and mileage calculations.
Injector cutoff is disabled when set to zero, and is disabled by default. To enable Injector cutoff detection, set the value equal to
seven times the engine size in liters, rounded up to a whole number. For example, for a 2.3L engine the value should be set to
2.3x7= 16.1
17. The value is not crucial and this calculation represents a best estimate.
When enabled and injector cutoff occurs, the Instantaneous MPG will read 999.9, and the Instantaneous Gallons/hour will read
0.0
Injector Cutoff should only be seen when de-accelerating. If during heavy acceleration, Injector Cutoff falsely occurs, decrease
the injector cutoff value by 20% or until cutoff no longer occurs. Setting the value too low will cause the Injector Cutoff never
to be detected.
NOTE:
Injector cutoff detection should be enabled prior to performing fuel calibration. If enabled after calibration, the
calibration procedure should again be performed.
NOTE
: If the open/closed loop indicator is not displayed on the gauge display or the loop is always open, then the vehicle does
not support Injector Cutoff detection and this feature should remain disabled. If the loop indicator is always open, this could
indicate an issue with your vehicle. If so, check for the presence of trouble codes.
NOTE:
Each vehicle manufacturer has their own algorithm for injector cutoff. Some require significant de-acceleration,
usually detected in terms of higher RPMs and a certain speed threshold, while others have a much lower de-acceleration
requirement.
NOTE:
When the transmission is placed in neutral, the vehicle’s injector cutoff function is disabled.
NOTE:
This is an optional setting and provides only marginal benefit to fuel usage and MPG calculations.
