Efficient Fuel Injected Vehicles

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Why an EFIE is needed?

Fuel Injection Basics
Fuel injected vehicles use a computer and sensing devices to sense and maintain the correct air/fuel ratio. One of the key sensing devices is the oxygen sensor. Fuel injected vehicles have one or more oxygen sensors installed in the exhaust stream. The computer extrapolates what the air/fuel ratio is based on the amount of oxygen in the exhaust, as reported by the oxygen sensor.

When a fuel saving device is installed, such as a hydroxy electrolyzer, the petroleum based fuel is burned more completely. One of the results of this is that there is more oxygen (and less unburned hydrocarbons) in the exhaust stream. This is a good thing, and is in fact, what we are trying to achieve. However, the computer will perceive this condition as a "too lean" air/fuel mix. In other words, what is now a desirable condition in the exhaust, will be interpreted as "not enough gas", and the computer will direct the fuel injectors to increase the amount of gas being pumped into the engine.

The result is that the oxygen sensor and computer prevent efficient combustion from occurring!

The Solution
The oxygen sensor "tells" the computer what the oxygen content is by providing a voltage on it's signal wire between 0 and 1 volt. 450 millivolts (.45 volts) means that the fuel/air mixture is correct. Higher values means the mix is rich (has too much gas), and lower voltages means the mix is lean. By adding voltage to the sensor's output, we can compensate for the additional oxygen in the exhaust.

The Electronic Fuel Injection Enhancer (EFIE) does exactly this. It adds a floating voltage to the top of whatever the oxygen sensor is putting out. It has an adjustment that allows you to control, to within a few millivolts, the amount of this added voltage. This allows the computer to be unaware of the additional oxygen content of the exhaust, and the electrolyzer can now achieve it's full potential in fuel savings.

Most cars have oxygen sensors both before and after the catalytic converter. The ones downstream from the converter do not need to be treated. Their data is used to determine when the converter has gone bad, but are not used in the air/fuel calculations. EFIEs are only needed for all upstream oxygen sensors.


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1 comment:

Anonymous said...

Hi Guys. On a lot of earlier fuel injected vehicles, for example, Jaguars and Range Rovers, the original (now 20 year old) EFI systems are no longer calibrated correctly (due to sensor, injector and ECU aging).

In some cases big improvements in fuel consumption, engine power and driveability are achieved by installing a later model engine management system like our engine management system.

Newer cars have more accurate AFR monitoring, and so don't go "out of tune" as easily as older fuel injected cars.

Cheers.