Originally Posted by
Cyberwolf
There is a world of difference between mechanical Fuel Injection like the ME 109 had and Electronic Fuel Injection.
Mechanical injection does not have the need of an O2 sensor, Manifold Absolute Pressure sensor, Throttle position Sensor, Electronic Control Unit and so on.
While Mechanical is just that it utilizes a high pressure pump and injectors set to pop at a certain time and pressure
Granted the electronic is far more fuel efficient but we all got by with the Mechanical for years and years.
Anyway back to the engine at hand here, W/O and O2 sensor or ECU I can't see how it can operate properly. The early Holley Projection unit's didn't have an O2 sensor and the ECU got lost constantly it was a Major PITA to deal with.
I'll let someone else try this out for now and see how well it does work, Besides I like to tune my engine's myself anyway.
It does not need an O2 sensor for several reasons:
-the engine design parameter is not hinged on stiochiometric AFR. That is a requirementonly to allow emissions controls devices to function as calibrated. It is NOT a necessary function for this system.
- O2 sensors cannot handle high percentage of contaminant in the fuel. It will plug up and fail ver quickly with 2stroke oil in the mix.
- An engine's ECU can determine load, and fuel demand by monitoring throttle position against rpm to determine load. Couple to a mass flow sensor (air intake sensor as described by HH) the ECI algorithm will determine correct fuel metering and can be designed to erroe correct and either slightly overfuel or underfuel (non prefered).
This engine is not flying long duration missions carrying relatively heavy payloads to the airframe. It is a toy airplane engine designed to take tuning out of the hands of Joe Soap.
Lastly, comparison with methanol fuel injection is comparing apples and oranges. Methanol fueled engines have high oil percentage and the oil presents problems to fuel metering