TPS break points at low throttle openings

[Meinolf]

Hi,

if I understand your question correctly then the answer is easy.

Looking at the first relevant voltage entries 0.176V - 0.157V - 0.137V the delta is 0.019V and 0.02V respectively, so the range is +/-0.02V for the inital entries. However, let's not forget that we are looking at millivolts here. I doubt that the average DMM has the accuracy and repeatability to operate reliably in the millivolt and below range. Test lead resistance, tolerances of the ADC, accuracy of the 5V supply to the TPS and the general operation of an ADC came into play.

Cheers
Meinolf

[audiomick]

10 hours ago, docc said:

+/- 15 mv, or a range of 30 mV, seems excessive. It must be tighter than +/- 9.8 mV at the low throttle angles (and for the baseline setting) . . .

 

1 hour ago, Meinolf said:

Hi,

if I understand your question correctly then the answer is easy.

Looking at the first relevant voltage entries 0.176V - 0.157V - 0.137V the delta is 0.019V and 0.02V respectively, so the range is +/-0.02V for the inital entries.

Just checking to see if I understand this right.

 

The point seems to be that the +/- 15 mV is less than the ~20 mV change between the figures at the bottom of the columns in the image that Phil posted here, and therefore an acceptable tolerance:

On 1/25/2024 at 6:54 AM, Lucky Phil said:

Here you go Docc. TPS lookup table in Volts.

Is that right?

[Meinolf]

22 hours ago, audiomick said:

The point seems to be that the +/- 15 mV is less than the ~20 mV change between the figures at the bottom of the columns in the image that Phil posted here, and therefore an acceptable tolerance:

Hi Mick,

no, 15mV tolerance is not sufficient. The total spread between the first breakpoints is ~20mV. Assuming you are  off +15mV from 157mV would put the TPS well within the range of the next breakpoint; target missed.

Even +/-10mV is stretching it thinly, +/-5mV is the highest tolerance I would go for.

Cheers
Meinolf

[Tomchri]

Had the pleasure of visiting Meinolf with a couple of ECU’s, since aim not a computer guy. BIG respect, so just listen to the gentleman. Not easy to get it correct first time, you will D feel the difference after a few try’s. So take your time doing it.

Cheers Tom 

[docc]

On 1/26/2024 at 12:46 PM, Weegie said:

Can I ask which ECU we're discussing here?

I'm going to reset the TPS and then do a throttle body balance on the Australia later this year, Hi Cam engine like the Daytona & 16M ECU.

Anybody care to comment if there would be any benefit in setting my TPS to 157mV per Meinolf recommendations?

 

On 1/26/2024 at 2:46 PM, Lucky Phil said:

15M. This isn't some magical Meinolf figure John it's the factory setting for the V11 Sport. Your bike is 150MV +- 15mv so 157 is well withing the tolerance.

 

Phil

This comment regarding the previous generation (16M) ECU and TPS setting makes me wonder if the  "+/- 15 mV" tacked on in the V11 Workshop Manual could have been another "cut and paste" holdover from the Daytona manual as we had seen with the driveshaft replacement phrase . . .
 

[docc]

I do not see that exact phrasing in the 1993 Daytona Workshop Manual, but would venture that this is the origin of the (questionable) +/- 15 mV language that originates from the Daytona (16M) procedure:

 

" For a more precise check. verify by means of a tester
that between poles «a .. and «b" of the potentiometer
:(3 and 2 on the connector)/here is a voltage of 150
mV +/- 15. with connector «A .. attached and the
ignition switch in the "ON" position;
loosen screws i,D·) (fig.93) and turn the body of the
potentiometer (with the throttle completely 'closed)
until the above value is obtained.
This checking procedure is valid for all models having
an lAW injection!ignition system. "

No wonder so many V11 have suffered running issues with this procedure potentially indexing the 15M map so far off! 

[Weegie]

10 hours ago, docc said:

I do not see that exact phrasing in the 1993 Daytona Workshop Manual, but would venture that this is the origin of the (questionable) +/- 15 mV language that originates from the Daytona (16M) procedure:

 

" For a more precise check. verify by means of a tester
that between poles «a .. and «b" of the potentiometer
:(3 and 2 on the connector)/here is a voltage of 150
mV +/- 15. with connector «A .. attached and the
ignition switch in the "ON" position;
loosen screws i,D·) (fig.93) and turn the body of the
potentiometer (with the throttle completely 'closed)
until the above value is obtained.
This checking procedure is valid for all models having
an lAW injection!ignition system. "

No wonder so many V11 have suffered running issues with this procedure potentially indexing the 15M map so far off! 

I looked in the workshop manuals for the early Daytona and a later one covering the Daytona RS/Centauro/Sporti

In the injection chapter both of them quote the 150mV +/- 15mV docc. Perhaps the US manuals are different but the statement is present in the copies I have, the +/- 15mV equating to a tolerance.

[docc]

5 hours ago, Weegie said:

I looked in the workshop manuals for the early Daytona and a later one covering the Daytona RS/Centauro/Sporti

In the injection chapter both of them quote the 150mV +/- 15mV docc. Perhaps the US manuals are different but the statement is present in the copies I have, the +/- 15mV equating to a tolerance.

Thanks, @Weegie. That is the same procedure I found in the Daytona manual (for the 16M ECU and not-sure-which TPS).  The V11 Sport/LeMans TPS/15M ECU benefit from a more accurate setting, 156.3 +/- 5 Mv (pending the various factors limiting this degree of accuracy).

The misleading statement in the V11 manual may have been simply carried over from the prior (Daytona) procedure (conjecture being investigated) and has led to various difficulties tuning the V11 TPS.

I am curious if this (misleading, IMO) section from the V11 Workshop Manual [provided to us by @Speedfrog] appears in this form in any of the manuals for the previous generation Guzzi with the 16M ECU:

[Weegie]

Couldn't see it in the manuals I referenced.

The procedure laid out for the Daytona etc: in the manual starts with checking the TPS before moving to vacuum balance on the TBs.

The Sporti as I recall has a different TPS but the procedure in the manual is the same