[kaysystems]

How did you determine yours was at 3' ?
I believe the US and Euro settings are different, slightly. I think you just set the throttle plates to where the tps reads 560 mv after 150 at complete closed. Maybe it was 540?

Used VDSTS to measure the 3 degrees, then backed off the throttle stop screw to check the baseline - 155mv. OK not the perfect way...but a good estimate.
DesmoTimes book says that 540mv = 3 degrees
I want to do the settings correctly in the spring, but not sure what the correct settings are.

Perhaps the manual is Euro?

Also wondering about the mixture setting. Everything refers to the idle setting. A don't spend too much time idling, so how do we check running mixture?

 

[kaysystems]

I used the value in the ducati manual, 2.3 degrees.
Once I set the throttle plate fully closed and reset with the VDSTS, it displayed 3.2. I don't know why this is. I asked LT and also tried to ask the VDSTS folks but did not get a good answer. So I just used the VDSTS to adjust the throttle so that the difference from the dead closed setting was 2.3 degrees (to 5.5 degrees in my case) and then reset with the VDSTS again. So at the end it read 3.2 degrees.
I don't think it's necessary to set the base to 150mV on the ST3. That's what the VDSTS reset is for. The ECU just uses relative voltage difference.

mmmm. I'm wondering if the reset should be done after all the idle is set. The 3.2 would make more sense, suggesting that fully closed should really be zero. In theory the TPS should never need a reset if we always start from zero.

Just trying to understand. This is my first 'electronic' bike

 

[kaysystems]

It may be different on yours but on mine I adjusted to the idle mV setting with the idle screw after setting the baseline at 150. That controls the fuel, not timing. Are you sure you're reading it right?

Have you ever reset the TPS? If done the way you did it, I do see the need for a reset, but once reset, life could be tricky to make sure the ECU understands that 150mv is actually zero on the throttle plate (and not a posible negative value)

 

[kaysystems]

Maybe I am making it too complicated. Should we reset the TPS at the 150mv setting or the 460? If resetting makes the ECU think that is the baseline it is important. If it should be done at the 150m position and it is done at the 460 position it is done wrong. (the ECU will think the 150 position is negative 3 degrees)

So my simple question. What position should the TPS be in to do the reset? Bearing in mind that after it is done the ECU thinks it is at 3.2 degrees.

Thanks

 

[kaysystems]

Please note that the ST3 ECU is different from earlier ST2 and ST4. The ST3 ECU has the ability to program the reference value which is the voltage at 2.3 degrees. This is what happens when you do the VDSTS reset.
If you think about it, the ECU doesn't care what the voltage is when the throttle screw is backed off all the way. It never gets there during normal running. All it cares about is what is the voltage at 2.3 degrees. From there it can use the relative voltage to figure out how wide the throttle is open.
The older ECU can only read an absolute voltage so that is why you must start out at a known value (150mV at the idle screw backed off).
Setting in the way I said in my previous post, the bike has excellent fuel economy and is running great with one exception - it sometimes does one "cough" when starting out from stopped. Also the cold start is a little hard - I have to rev it up for a couple seconds after starting or else it will die out. But this could be a leaky injector or something.

Thanks Colin

I think my brain is getting this sorted out. I will need to worry about the cold start more than you. Just went out for a while this morning. It was 29 degrees F when I started. Winter's coming.