gee,i dont know beez,

its generally about the 0.5V closed>>>> 4.5V WOT range.
be good idea to consult the service manual for your particular motor u want to "calibrate"
i just use a data-logger & even if it was outta spec it can be just re-calibrated in the software,so no idea about voltage values beez,sorry,not even for my own tps lol.

im surprised the Y4 uses those values & it wasnt like totally reversed or something,in keeping with the rest of its design principles.
best to get an obd2 scanner(if your on obd2 of course) that gives sensor readings & calibrate it with that to see if ecu is indeed reading 0% > 100% throttle.

but if u can find the factory voltage figures for your tps then u should be fine.

if your having tps problems,good thing to check first is that your getting a good 5V reference volatge from the ecu across the yellow & green wires at the tps plug.
then go onto check the signal voltage back to the ecu across the red & green wires.

that idle valve beez,got any pics of the other bit that attaches to it?
is it a 3 wire plug that attaches?
must be one of those stepper types.

btw "calibrate" all your "corobarilaratededserers"