yeah, it'll make a difference. Here's what I got.
Through ECU- Signal-Red wire= 4.99v
Output to ECU-Throttle plate bottomed close- Yellow wire=.396mv
Throttle plate full opened- Yellow wire=4.69v
Then, with an external 5v source that actually reads 5.99v
As you can see the output voltage rises as the input rises, throwing the whole thing out the window!!
Also, you can see that my TPS is Shit!!
I haven't been able to get this thing close to the required 150mv close, 420-460mv idle, it's more like 600mv at idle. But it's a trackbike so it still runs OK. Still I wish I had another used one (new one's are $$$$) to play with.
The above numbers are with the TPS removed and operating it from the back, stop to stop. Total range= .396MV-4.69V