How does eFlexFuel works?

eFlexFuel controls fuel delivery

eFlexFuel working princible

The operating principle of eFlexFuel is based on processing the fuel injection signals received from the electronic control unit (ECU) of the car engine. As a result, the fuel injection is entirely controlled by the eFlexFuel conversion kit, and the car’s each fuel injector is controlled separately. Therefore, eFlexFuel adapts perfectly to different fuel injection schemes.

Changing the injector opening time

Since the energy content of E85 fuel is lower than that of regular gasoline, more fuel needs to be injected during each injector cycle. Typically, the increase in the amount injected is about 28%. This amount decreases with increasing gasoline content of the fuel mixture. This regulation is done automatically by eFlexFuel.

Adaptive system

eFlexFuel recognizes the ethanol content of the fuel mixture automatically and modifies the fuel injector signals accordingly. In this way, the air-fuel ratio is always optimal, and the fuel consumption and emissions are minimized. When refueling, the mixture recognition is done automatically if it has changed. This process is described in more detail in the manual.

Operating principle

eFlexFuel uses an ethanol sensor to recognize the fuel mixture. Recognition happens in real time and the operation is fully automatic at all times. We use the same ethanol sensor that is used by car manufacturers in factory-made flex fuel vehicles.

eFlexFuel adapts to the ambient temperature

eFlexFuel is equipped with an external temperature sensor that is used for adapting the device operation in accordance with the engine’s temperature. This will enable engine start in all climatic conditions such as in extremely cold weathers that are usually more difficult for the E85 fuel. The temperature adaptation is active only during engine start. eFlexFuel has been tested in temperatures as low as -30 °C (-22 °F). When comparing to the use of bare gasoline, however, the use of E85 can result in worse cold starting capability in extremely cold weather.

Adaptive cold start function

eFlexFuel learns from failed cold start. The latest device version includes an adaptive cold start function. This feature allows better cold starting with all types of vehicles fully automatically.

Notice! Possibly weaker cold start ability is a result of significantly higher ethanol content of E85. eFlexFuel automatically adds fuel feed linearly to ease cold starting when the engine block temperature is low.

Cold start aid

There are numerous ways to improve engine cold starting when E85 fuel is used in extremely cold weathers. The best and the most economical way is to use an engine block heater. If such is not available, we recommend adding 5 - 10 % of regular gasoline to the E85-based fuel mixture.