Throttle Position Sensor

[dlaing]

I posted the how to here http://www.v11lemans.com/forums/index.php?showtopic=12204

Mike Stewart took this photo that nicely shows which two wires to probe (the outer two)

Here is direct link to photo

http://img213.imageshack.us/img213/6420/tpsvoltage02xe1.jpg

EDIT 02.02.08 But it seems to be missing at the moment...

Here is a new version

By dlaing at 2008-01-22

[dlaing]

ALdad brought up an interesting problem.

He got a high idle after adjusting the TPS.

Assuming I diagnosed it correctly, the solution is probably just to simply make sure the Right throttle really is closed, but this gets me thinking that maybe the WOT TPS, Wide Open Throttle Throttle Position Sensor measurement system would be better.

The linkage should still be disconnected, but the results might be more consistent and there would be no need to back off set screws or choke.

The one potential flaw to the method, is that we don't know if the throttle bodies are all built to the same exact dimensions.

The question is: If we set to 150mV closed will the WOT measurement always be the same from bike to bike?

If so, I think it would be a better method.

[dlaing]

From ALdad's thread,

raz replied to my post

This is just a guess and my gut feeling, but I don't expect that to work very well. This will set it in the less critical end. I'm not sure how to put it.

 

Also, if it would work we still can't set the idle, only the base (opposite of 150 mV). Right? And since the linkage is disconnected, are you thinking we should hold the butterfly at WOT by hand? Or do I misinterpret what your are thinking?

 

Last, most multimeters (I think all three of mine) will only give two decimals at that range. My reading at WOT right now is 4.84V (I think I settled for 165 mV when I set the TPS days ago)

 

Other than that, it's an excellent think-out-of-the-box idea

Good point about the WOT TPS being the less critical. So, if the WOT to closed difference is not the same on all bikes, it would likely cause problems.

Yes, with linkage disconnected, one would have to hold the right throttle body open by hand. I don't think this would be too difficult.

Oh, and very good point about the multimeter.

I'll have to check mine!

I read the WOT reading months ago, so I don't recall, but I too may have lost a decimal of accuracy.

I don't think that would be acceptable.

[raz]

Good point about the WOT TPS being the less critical. So, if the WOT to closed difference is not the same on all bikes, it would likely cause problems.

Yes, with linkage disconnected, one would have to hold the right throttle body open by hand. I don't think this would be too difficult.

Oh, and very good point about the multimeter.

I'll have to check mine!

Good news: actually my point about the multimeter was invalid, as we can measure between +5V and slider, instead of slider to ground. Bad news: the potentiometer is logaritmic, so it is less steep at that end. Much less, I think. We will miss some resolution.

 

I rechecked, and I remembered wrong: my base TPS setting is 175 mV when WOT is 4.85 V. That's because I set it against some special recommendation for a custom map I'm going to try out.

 

Anyway, when measuring between +5V and slider, my WOTPS is 141 mV. The repeatability when letting go and pulling again varied within 4 mV around that figure over 10-20 pulls.

 

My nominal 5V measures to 4.98V. Adding 4.85 and .141 is... 4.991. OK, fair enough (different ranges on cheap multimeter). Now the interesting question is if doing this on different bikes will render the same. If nothing else, this method can be used to check a specific bike for unaltered TPS, with all the benefits you mentioned. But that depends on how much sensitivity we lose because of the logaritm.

 

One thing I really don't like about setting the base the normal way is snapping the butterfly against the TB without a stop. I have read it can be damaging, and my young jedi tech feelings says the same when I do it.

[raz]

Now that I think of it, my readings indicate it would be close to 150 mV in both ends, had it been set correct at the bottom. Maybe that is not a coincidence.

[dlaing]

If nothing else, this method can be used to check a specific bike for unaltered TPS

Yes, and if one marks down the exact number after a tune-up, future tune-ups could be repeated with the WOTTPSmV reading!

But the balance of the throttle bodies could throw the reading off if the linkage is not disconnected.

Some bikes will tend for the right TB to top out at WOT and some the left TB. Individuals could determine their bikes nature and go from there. But that is getting too complex for a general howto instruction.

 

One thing I really don't like about setting the base the normal way is snapping the butterfly against the TB without a stop. I have read it can be damaging, and my young jedi tech feelings says the same when I do it.

Yes, in ALdad's high idle thread, I was unsure how to tell him to gently force the butterfly all the way home. Only a little pressure is needed. The visual confirmation that the 'choke' is not getting in the way is important, but the throttle body can still stick and gently pullling the lever closed will change the TPS reading, at least in my bike's case.

[dlaing]

Now that I think of it, my readings indicate it would be close to 150 mV in both ends, had it been set correct at the bottom. Maybe that is not a coincidence.

FASCINATING!

[pete roper]

Look, I know I'm not an *expert* but is there any reason why you can't st the TPS to it's required voltage with the link rod connected by simply using the idle stop screw. This will get you the correct degree of opening for the map to work as it should. Then if the idle is too high of low simply set it with the air bleeds, it's what they're there for.

 

I must say that I've found this to be perfectly satisfactory as long as nobody has been farting about and moving the TPS willy-nilly. Obviously if the idle speed can't be set correctly with the bleeds then you have to start fiddling about with the TPS but on most of the V11's and Calis I'v dealt with this seems to work OK??

 

Pete

[dlaing]

Look, I know I'm not an *expert* but is there any reason why you can't st the TPS to it's required voltage with the link rod connected by simply using the idle stop screw. This will get you the correct degree of opening for the map to work as it should. Then if the idle is too high of low simply set it with the air bleeds, it's what they're there for.

 

I must say that I've found this to be perfectly satisfactory as long as nobody has been farting about and moving the TPS willy-nilly. Obviously if the idle speed can't be set correctly with the bleeds then you have to start fiddling about with the TPS but on most of the V11's and Calis I'v dealt with this seems to work OK??

 

Pete

Frequent tuneups of simply balancing the TBs and setting the idle speed, and idle TPS reading can be done as you suggested.

If the TPS sensor is not far from 150mV you can set the TPS to it's required voltage with the link rod connected by simply using the left idle stop screw. But one does not know if the 150mV is off unless you disconnect the linkage, etc.

Taking the reading at WOT may offer a quick and easy decent impression, but as we mentioned, there are some potential gotchas that could make the reading inaccurate.

The instructions we created start with setting the 150mV setting. It is not always necessary to check the 150mV reading, but it really is not that difficult to set it properly and exactly if you follow the instructions.

Give it a try. You will find it will add less than five minutes to the tuning process, and then you will be sure it is set correctly.

Also, note the WOT setting. If you are familiar with the bike, it can be used to determine a gross slippage in the TPS setting.

[Greg Field]

Regarding Greg's comments: There are many sources of recommended degrees open at idle. I don't think it is appropriate to highlight one out of the many out there. Besides, it does not agree with the OEM sensor specs.

 

I've made the other changes you suggested.

 

Umm . . . those were OEM recommendations, from the Guzzi instructions that come with the Ti exhaust. They are valid only if you use one of the two (late or early) race ECUs provided with the exhaust kit. If using one of these two ECUs, these recommendations ARE the only ones out there. I believe it unwise to assume they are not valid.

[Ryland3210]

For those who wish to go directly to the carefully researched and proven step-by-step tuning method, you can go to the How To section:

 

http://www.v11lemans.com/forums/index.php?showtopic=12204

 

[Greg Field]

I see. It would seem that the procedure has now ossified to become dogma. So be it.

 

Still, one wonders if any of the creators of this procedure have tuned a bike that has the Guzzi race ECU and pipes? If not, how can the procedure be proven or even tested for these machines? If so, maybe it works for some machines under the particular use that those owners put their machines to but wouldn't for others?

 

Here's a little story. We at our shop have had two '04s that owners themselves fitted with the Ti pipes and ECU. These folks followed their normal tuning procedures and never could get the bikes to run right. These stumbled and hesitated under certain conditions of part throttle and small throttle changes and weren't as smooth-running as before and one pinged badly. Both owners later sold their V11s on consignment or traded them in because they could never get them to run right. One of these folks was an auto mechanic. In both cases, with 10 minutes of tuning, our service manager had them completely sweet-running. One he told me was the best-running V11 he had ever ridden, and he has ridden hundreds of V11s. Also, he has personally owned three V11s that had the Ti pipes and one with other pipes. He insisted I take it for a ride, and it ran perfectly. I deliberately tried to make it misbehave but it didn't. It ran as good as mine with a PCIII and custom map, even though it had neither, just a proper tuning for Ti pipes.

 

You might at least consider that the Guzzi race ECU is different enough that it could benefit from altered tuning compared to that of the normal ECU.

[Mike Stewart]

Greg ,

 

Story 1,

 

Lets go back in time a few years to when the V11 Sport first came out. There were a few driveability problems with the bike, mainly a big flat spot on acceleration and stalling (if my memory serves me right). Some bikes were real bad, others seemed to run fine. There was a big debate back then on how to adjust your tps, yes the same why you guys are talking about. I have done it that same way but still was not totally happy with the way the bike ran. I ended up buying the Powercommander and while no maps worked well for my bike, I played with adding and subtracting fuel through the whole rpm range till the bike ran beautiful (even had to subtract fuel at idle). The reason I believe the bike needed a different map was because of my low tps voltage I had compared with the bikes the maps were made for. While I corrected the way my bike ran with the PCIII, many adjusted their tps voltage up to .5 volts with great improvement.

 

Story II,

 

I purchased a 03 Rosso Corsa, the bike ran beautiful off the show room floor. A few weeks later I installed Mistrals slip-ons and now the bike ran terrible, spit and spuddered in the lower rpm range. Checked the tps voltage .466 volts and left it there. I installed the PCIII with a map from Todd Egan and the bike ran great again. The map I installed was way different than the map I had in my 2000 Sport. I do believe that besides the tps voltage difference that there is a stock map difference between the early 2000 Sport ECU and the 03 ECU's. My early bike would also ping at 3000 rpm on hot days which the PCIII helped but did not cure, the 03 bike never pinged , perhaps another map change in the ECU

 

So what I am trying to say is, the early bikes seem to be quite different than the 2003 and newer bikes. I am not saying to play with your tps, if your bike runs good, leave it alone.

 

It is great to hear from Greg and the experences he has come across in his shop , I have heard many driveability complaints of the Ti ECU and he has cleared up many questions/myths in my mind

 

Mike

 

 

 

I see. It would seem that the procedure has now ossified to become dogma. So be it.

 

Still, one wonders if any of the creators of this procedure have tuned a bike that has the Guzzi race ECU and pipes? If not, how can the procedure be proven or even tested for these machines? If so, maybe it works for some machines under the particular use that those owners put their machines to but wouldn't for others?

 

Here's a little story. We at our shop have had two '04s that owners themselves fitted with the Ti pipes and ECU. These folks followed their normal tuning procedures and never could get the bikes to run right. These stumbled and hesitated under certain conditions of part throttle and small throttle changes and weren't as smooth-running as before and one pinged badly. Both owners later sold their V11s on consignment or traded them in because they could never get them to run right. One of these folks was an auto mechanic. In both cases, with 10 minutes of tuning, our service manager had them completely sweet-running. One he told me was the best-running V11 he had ever ridden, and he has ridden hundreds of V11s. Also, he has personally owned three V11s that had the Ti pipes and one with other pipes. He insisted I take it for a ride, and it ran perfectly. I deliberately tried to make it misbehave but it didn't. It ran as good as mine with a PCIII and custom map, even though it had neither, just a proper tuning for Ti pipes.

 

You might at least consider that the Guzzi race ECU is different enough that it could benefit from altered tuning compared to that of the normal ECU.

[dlaing]

I see. It would seem that the procedure has now ossified to become dogma. So be it.

No, the procedure has not ossified to become dogma.

Perhaps this thread has. Maybe this thread should be unpinned.

 

Still, one wonders if any of the creators of this procedure have tuned a bike that has the Guzzi race ECU and pipes? If not, how can the procedure be proven or even tested for these machines? If so, maybe it works for some machines under the particular use that those owners put their machines to but wouldn't for others?

The procedure is not recommended for Ti ECU bikes.

Likewise it has not been tested for any aftermarket ECUs nor Harley Davidson TPS.

This procedure is in my opinion the best freely available TPS set up instructions.

I am sure the Ti ECU owners would appreciate a How-To.

We considered adding the numbers you previously posted for the Ti-ECU, but you were not sure the difference was meaningful. And we wanted to keep the instructions simple. We could create an alternate complex instruction set.

 

I was just reading the instructions included with the Guzzi Ti pipes. They specify different tuning for the bikes with the front crossover and the bikes without the crossover. Fr the non-crossover bikes, it says set the TPS to 3.8 degrees +/- 0.1 degree, which it says corresponds to 550 mV +/- 5mV. For the crossover bikes it says set the TPS to 2.9 degrees +/- 0.1 degree, which it says corresponds to 465 mV +/- 5mV.

 

Perhaps this difference is meaningful and needs to be taken into account in the procedure set forth in this thread?

Do people get the instructions when they buy the Ti kit?

Perhaps someone who knows how to tune the Ti Mufflers could write some instructions.

[dlaing]

Greg ,

 

Story 1,

 

Lets go back in time a few years to when the V11 Sport first came out. There were a few driveability problems with the bike, mainly a big flat spot on acceleration and stalling (if my memory serves me right). Some bikes were real bad, others seemed to run fine. There was a big debate back then on how to adjust your tps, yes the same why you guys are talking about. I have done it that same way but still was not totally happy with the way the bike ran. I ended up buying the Powercommander and while no maps worked well for my bike, I played with adding and subtracting fuel through the whole rpm range till the bike ran beautiful (even had to subtract fuel at idle). The reason I believe the bike needed a different map was because of my low tps voltage I had compared with the bikes the maps were made for. While I corrected the way my bike ran with the PCIII, many adjusted their tps voltage up to .5 volts with great improvement.

Was your TPS voltage at idle below .5V? If so, than you were not using the method we created.

If a PCIII map is used, the bike should be tuned to the specs that the bike was mapped to.

Unfortunately people simply take there bikes to dyno for mapping without giving the bike a proper tuneup, and then they share their maps.