One EFI question

[MtnEX]

Answer me one question since I don't understand....

If this EFI system can't sense and adjust itself for a change at the air box, or a change at the exhaust silencer.....

How can it adjust itself for altitude and temperature?


I don't understand really because I don't know much about EFI and have never "tuned" it. All I've ever done is replace some sensors.

[MtnEX]

Oh... and I understand it does not have an o2 sensor to read exhaust gases... which makes it an open loop system...

So I can see how it can't adjust for getting leaned out, etc... can't adjust for what it can't see.



So it is only reading what is "incoming" to the engine right? So what kind of sensors does it have?

If it can tell altitude and temperature, and adjust for that, I can't see why intake changes would be a problem unless they went beyond the range of compensation that is programmed in.

[08mxkfx]

it has a barometric pressure sensor that is mounted right by the throttle body under the gas tank. and it has an intake temperature sensor that is mounted on the intake tube right infront of your airbox.

[MtnEX]

Originally posted by 08mxkfx
it has a barometric pressure sensor that is mounted right by the throttle body under the gas tank. and it has an intake temperature sensor that is mounted on the intake tube right infront of your airbox.

Thanks!
Now it makes sense.
Only 2 sensors, one for each, and that is all it can do.


Now... when you add what is available out there today in the way of controllers, then you are getting to program a new pre-determined map for the injection to follow just like it has now.... but is the aftermarket controller able to also read these sensors and adjust as if it were stock?

[k4f5x0r]

i think ive figured this out..

the two sensors take into account the air moisture etc and then determines the ammount of fuel that needs to be delivered.. then that passes through the PC3 or w/e commander because thats where it plugs into. the pc3 then adds a cerntain % of fuel based on the map you have. then it is sent to the injector and teh fuel is distributed..

thats the only way i could think of. and it seems to make perfect sense.

[miles Machine]

k4f5x0r-- your almost dead on. the ECU gets all the signals from the sensors, processes it as it normally would but instead of going to the injector like it would stock it must first go to the fuel controller then the fuel controller changes that signal to the meet the needs that are set from the downloaded map. (The fuel controller is hooked in-line between the ECU and the Injectors)

[k4f5x0r]

knew i was close :D . and thats what is still lacking in these bikes. they need to have the design of a car. so its just bolt on and go. i also they they should make them direct injected ;) . slightly more power and a cleaner burn :cool:

[631kfx400]

Originally posted by k4f5x0r
knew i was close :D . and thats what is still lacking in these bikes. they need to have the design of a car. so its just bolt on and go. i also they they should make them direct injected ;) . slightly more power and a cleaner burn :cool: i also they they should make direct inection. makes so much sense:scary:

[MtnEX]

Yeah... lawn and garden engines have digital direct fuel injection that is fully monitored, metered, and adjusted on the fly in real time.

I'm not super sure why EFI is so much farther behind in powersports. It doesn't make a lot of sense.



There is a new add-on full closed loop self-adjusting tuner on it's way............... I've seen it but I am not yet certain it will be available for the KFX450R.

We'll see.