Last weekend I flew an aircraft fitted with a fuel injected Jabiru engine which Jabiru France has been working on. It has a multipoint programmable fuel injection system.
We (myself and Alexandre Patte) flew a guepy (wasp in English) which also has several other mods, including different piston rings, modified pistons and valve guide seals. there is a 1000m runway there, but Alex told me to take off on the 100m patch of ground normally used for parking in front of the hanger! 80m was enough, and a flat field beyond in case of problems...
On starting the engine 'hunted' for a minute or so because the cold start mixture was too rich, but when warmed up it ran just like any other, perhaps smoother. On take-off and cruise the engine had a slightly 'harder' note to it than I'm used to and the engine seemed a bit smoother with a constant engine note.
Alex seemed to think that the fuel consumption was a bit better, but early days yet. No sensors were fitted to the test aircraft to verify EGT’s.
Advantages:
>No carb ice
>Optimal mixture for each cylinder (not much plenum for fuel-air mixing with carby)
>Possibly better fuel consumption
Disadvantages:
>Running of engine becomes totally dependent upon electrical system working : no power = no engine!
>8A current consumption (although 15A alternator now available)
>More weight (fuel pump, ECU, electrics, extra battery maybe)
>ECU, pump or sensor failure could mean no engine
