Wondering about the URD 7th injector and how it works when controlled by a UCON. Does the 7th only spray fuel under acceleration - over a certain engine load (as needed)? Or does it spray all the time? And if it sprays all the time, is the duty cycle for the other 6 reduced to compensate at all?
How does the URD 7th injector work?
- Thread starter Tom2769
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Gadget
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The standard calibration activates the 7th based on the throttle position. The amount of fuel is set by percentage of total fuel flow. When the 7th is active the amount of fuel from the primary injectors is reduced so you always have the correct amount of fuel, it just comes from different places.
The logic can over ride the base settings if needed to compensate for a sudden loss of fuel pressure, or spike in fuel pressure and drive the primaries and 7th to whatever duty cycle is needed to maintain proper fueling. This is part of the self tuning function. If it can't compensate for an odd condition it will set the Guardian to protect the engine.
With the TRD supercharger with the older style 3 lobe rotor pack, efficiency nose dives when the boost goes up and putting fuel through the blower with the 7th cools the compressed air and helps seal the rotors better and that reduces the black flow problem with the 3 lobe rotor.
G
The logic can over ride the base settings if needed to compensate for a sudden loss of fuel pressure, or spike in fuel pressure and drive the primaries and 7th to whatever duty cycle is needed to maintain proper fueling. This is part of the self tuning function. If it can't compensate for an odd condition it will set the Guardian to protect the engine.
With the TRD supercharger with the older style 3 lobe rotor pack, efficiency nose dives when the boost goes up and putting fuel through the blower with the 7th cools the compressed air and helps seal the rotors better and that reduces the black flow problem with the 3 lobe rotor.
G
I've tuned a fifth injector (on a Prado 4 Cylinder) and I activated it based on engine load, measured by MAF. So when load and RPM reaches a specific threshold I enable the fifth injector to compensate for fuel loss resulting from the low capacity of the stock injectors.
