TPS voltage questions

[iletts]

Having recently synched TB's and reset TPS, I noticed that the TPS reading drops from 389mV with the igniton switched on to 372mV with the engine running. It doesn't seem to make a big difference, but why does the voltage drop when engine is running, and should it be set with engine running or stopped?

Also, the TPS voltage peaks at 4.66V at about one third throttle opening (correctly), so how does the engine management system know how much fuel to chuck in at the higher throttle settings? There isn't a mass air flow sensor, which is how cars tend to do it. I can't see it working off the revs (hall sensor) as that would not work for decceleration

bike is 2001 1150 (motronic 2.4?)

answers on a postcard please......................

 

[Pauly S]

if you measure the other track on the tps you will see its a linear increase all the the way from tickover to full bore.i think there are two resistance tracks down the lower end of the throttle range , where you spend most of the time ,and on resistance track one, you are right , it plateaus around 1/3 throttle at about 4.6volts all the way to full bore.thats where the second track comes in, it knows when you are above 1/3 throttle by resistance track one(4.6v) and then watches resistance track two for the correct fuelling from 1/3 to full bore.. thats what i found out, trying to stop a full bore stall.regards Paul

 

[iletts]

Thanks Paul, makes sense - damn sneaky...........