EFI explained

[BuellyBagger]

I am always bothered by posts where members come up with goofy mysterious things about simple EFI for example "u must connect to ECM software to adjust idle" or "engine temp makes a difference when reseting the TPS to zero" (it does make a difference when setting the idle ) so this link i think will be a good guide to simple EFI

http://www.nightrider.com/biketech/motorcycle_efi_basics.htm

 

[BuellyBagger]

Oh i have to add, i am NOT a EFI genious!!! in fact i know very little so dont burn me if there happens to be something off on that link just looked like a good simple description of "How it Works"

 

[BuellyBagger]

SO????? what does everybody think, good diagram and explination?

 

[BuellyBagger]

nice/\ luigi i like where this is going, by all means continue

I had beleived b4 reading that web page that the throttle cable actuated a sharp spike that stabbed an angry bull in the ass causing it to rear up and take off wildly

 

[konarider94]

"engine temp makes a difference when reseting the TPS to zero"  (it does make a difference when setting the idle )

one could argue thermal expansion in the throttle body and resistance changes in the tps sensor at operating temperature affect the tps zero. But I doubt its very much since the parts are so small. Ive only reset mine once when it was kinda warm, and every time i check it it returns to zero on its own so i just crank the idle adj back up to where it was. If you back off your idle adjust all the way and ecmspy reads 0 there is no sense in clicking the button on the screen to change the 0 to a 0. only if it has drifted by some percentage should you need to rezero it.

also the tps sensor has no correlation to the exhaust you have. that bothers me most. people say you need a tps reset if you change your exhaust, do the breather reroute, or change your brake pads (i might have made that one up buts its equally as ridiculous)

 

[BuellyBagger]

i agree kona, and i wasnt tryin to pick out ur post, i figured u were thinkin that it would make a slight dif. (from expansion) but it would make such a minor difference it would unmeasurable i assume.

I really had no knowledge of how fuel injection worked, mostly for lack of wanting to know, until my bike had issues. I found that the basics of it, what has to do what to make it work, are pretty simple. Tuning and adjusting maps is still beyond me, i havent even taken a crack at it, bcuz i dont have the time or desire, but im sure that it would be something i could learn and really ne of us could figure out (doesnt mean we'd be good at it).

I dont know how the TPS reset became such a mythical procedure, but all ur doing is showing the ecm when the throttle is completely closed, so it can calculate everything beyond that.

 

[konarider94]

i agree kona, and i wasnt tryin to pick out ur post, i figured u were thinkin that it would make a slight dif.  (from expansion) but it would make such a minor difference it would unmeasurable i assume. 

x2

I dont know how the TPS reset became such a mythical procedure, but all ur doing is showing the ecm when the throttle is completely closed, so it can calculate everything beyond that.

I wonder this all the time. Its suggested so often i hate suggesting it even when it might actually be the problem. I cant help but think "right now im that guy that says a tps will fix everything."

 

[BuellyBagger]

the tps thing isnt just buells... my expedition had a historic code for high tps voltage so i googed it. i ended up @ a f-150 lightning website where there's hundreds of posts about reseting your tps and how much of a fix all it was.

 

[jimijeans]

Throttle Position Reset is the First thing to get out of the way if you have an Idling issue OR a problem with starting the Engine. Then Spark and Fuell. At least the Older Buells have an Idle Screw. This goes for any vehicle for todays standards of Diagnousing problems.
Once the TPS is done the next step is to find the actual problem if it goes farther than that. With the Buells there is several areas that needed more testing and development. But go ole HD pulled out the Rug and here we are. All Vehicles somewhere down the line wears out tps pretty Quick That is one part that takes a beating.
So it is sometimes going to be Check your Tps if you have Fuell & Spark but no starting then possibly the Starting and Idle will be 1st and easiest to check. Also it is cheap to fix a TPS and not much down time. Yeah it sounds like a Record stuck in place. The Forums that are all over the Internet save us all from the Dealer, well most of the time, Have fun learning your UniQue ride. She is in a class all by herself. Ride Safe.*Jimi