Ducati Monster Forum

Moto Board => Tech => Topic started by: booger on August 26, 2017, 07:48:44 PM

Title: TPS- what's the position supposed to be
Post by: booger on August 26, 2017, 07:48:44 PM
Just got the bike put back together with the reflashed ECU and had to reset the TPS, it was at 2.9 degrees. Reset with GuzziDiag, and its now at 2.6. What is it supposed to be? Bike started and seems to run well. Also can anyone tell me the normal idle speed? It idles at ~1500. 2007 S4RT- thanks
Title: Re: TPS- what's the position supposed to be
Post by: booger on September 01, 2017, 09:40:16 AM
LOL is this on
Title: Re: TPS- what's the position supposed to be
Post by: koko64 on September 01, 2017, 10:20:09 AM
I dont know off hand, but have you checked the bikeboy.org site for tps settings? A wealth of information there. Factory workshop manual?
Title: Re: TPS- what's the position supposed to be
Post by: Dirty Duc on September 01, 2017, 10:21:22 PM
So, as I understand it, the actual position of the TPS reading isn't particularly relevant. When you "reset" it, you basically tell the computer (ECU) that the current position equals zero. The interface between the throttle plates and the sensor bits is plastic, and microscopic wear might have an effect.

Title: Re: TPS- what's the position supposed to be
Post by: Speeddog on September 02, 2017, 08:27:01 AM
Quote from: Dirty Duc on September 01, 2017, 10:21:22 PM
So, as I understand it, the actual position of the TPS reading isn't particularly relevant. When you "reset" it, you basically tell the computer (ECU) that the current position equals zero. The interface between the throttle plates and the sensor bits is plastic, and microscopic wear might have an effect.

More or less right.

The TPS reset tells the computer that "whatever the TPS voltage reading is right now, use that as 2.6 degrees* throttle opening".
* - The actual number varies by model

Whether this actually sets it *correctly* is based on the precarious assumption that the throttle blade position is correct.
If anyone has ever altered the throttle stop screw position, then the TPS will not actually be set correctly.
Brad Black has a detailed setting procedure here: http://www.bikeboy.org/ducatitps.html

Idle speed is controlled directly by the ECU via the idle air servo valve.
On some models, the idle speed is user adjustable, not sure if the S4Rs is or not.

I'm working with an uncooperative S4Rs now, if I find out anything relevant to this thread, I'll post it up.
Title: Re: TPS- what's the position supposed to be
Post by: booger on September 02, 2017, 11:10:34 AM
Thanks for all replies. Speeddog what are you using in your shop to sync TBs? I have a Twinmax and I swear I hate that thing. Just want to find a pair of simple vacuum gauges and I got a set off Amazon but they sucked (too cheapo, zero adjustment screw was fuxxed) so I sent them back. Bike's lumpy and snatchy below 3500 so I'd like to do what I can to smooth it out. Air bleeds on this bike may have been touched, vert cyl is all the way in and horiz is like maybe 3 turns out.
Title: Re: TPS- what's the position supposed to be
Post by: Speeddog on September 02, 2017, 11:45:45 AM
I'm using a simple manometer with ATF in it.

Close the air bleed screws, and disconnect and plug the hose for the idle air valve.
Then you can actually sync the TB's themselves.
You'll need to shim between the throttle stop screw and the cable spool to get it to idle.
Title: Re: TPS- what's the position supposed to be
Post by: booger on September 02, 2017, 12:23:14 PM
Quote from: Speeddog on September 02, 2017, 11:45:45 AM
I'm using a simple manometer with ATF in it.

Close the air bleed screws, and disconnect and plug the hose for the idle air valve.
Then you can actually sync the TB's themselves.
You'll need to shim between the throttle stop screw and the cable spool to get it to idle.

Thanks Speeddog. So I guess the idle air valve interferes with throttle balancing somehow? Is this IAV the same as the stepper motor? If so it figures that if the valve is constantly working in real time to control idle then setting the throttle balance properly could never work. Also, looking at the parts manual the stepper motor has three hoses. Any more detailed advice on this would be really helpful, like I can probably figure out how to rig the throttle to idle but which hose to disconnect and plug is where I'm lost.
Title: Re: TPS- what's the position supposed to be
Post by: Speeddog on September 02, 2017, 03:19:48 PM
The hose that connects to the fitting on the bottom of the airbox.

Pull the hose off of the fitting, and plug that end of the hose.
Title: Re: TPS- what's the position supposed to be
Post by: itsamonster on September 05, 2017, 12:04:01 PM
I'm reading this with interest speeddog, keep the useful info coming.
Cheers.
Title: Re: TPS- what's the position supposed to be
Post by: booger on September 05, 2017, 03:28:45 PM
Yeah thanks Speeddog