Newbie TPS Questions

[cycdude6]

Hi all, I've read much of the TPS thread and still have a question as well as a comment from a Guzzi mechanic.

My questions are these, 1)where and how do you pick up the millivolt readings? 2)Is there a picture anywhere? 3) I have a fluke meter with only one voltage setting, will that be accurate enough?

Secondly, the mechanic states that under no conditions should I attempt to adjust the TPS on an '04 V11, he claims that it is very very difficult to bring it back to factory specs if I mess it up.

 

Thanks guys (and ladies!)

[Garsdad]

Hi all, I've read much of the TPS thread and still have a question as well as a comment from a Guzzi mechanic.

My questions are these, 1)where and how do you pick up the millivolt readings? 2)Is there a picture anywhere? 3) I have a fluke meter with only one voltage setting, will that be accurate enough?

Secondly, the mechanic states that under no conditions should I attempt to adjust the TPS on an '04 V11, he claims that it is very very difficult to bring it back to factory specs if I mess it up.

 

Thanks guys (and ladies!)

 

 

I slide a sewing pin into the back of the plug and pick up the voltage there. There are lots of references as to which wire- my copy of Guzziology is in the garage and it's cold out there, so I am not going to look it up right now. As long as your meter reads millivolts, you are fine. If the smallest increment is a tenth of a volt, you are screwed. They are less than $10 for a decent one... invest. Also, it is much easier to use leads that have little clips or hooks on them them.

 

It is a SENSITIVE little bitch, so move it slowly, but even if you move it way out of whack it isn't that hard to put back and start over. Me thinks your mechanic wants to scare you into having him do your work for you.

[docc]

On the 2000 Sport: ( I don't know if the wires changed on the later harness; a quick check of Carl's wiring diagram will tell)

 

(+) - black/violet

(-) - violet

 

The earlier Sports had the ECU connector exposed and was easier to get to. I've never "back probed" a later computer. Some have been able to get to the connections at the TPS. I found that to be difficult.

 

It is very sensitive and will tend to migrate as you tighten it, so it takes a lot of fiddling to get right. Normally, a dedicated owner will mess with the thing much longer than a paid wrench to get it close to perfect.

 

Oh, and it helps to replace the fasteners with conventional hex drives.

[Ryland3210]

Hi all, I've read much of the TPS thread and still have a question as well as a comment from a Guzzi mechanic.

My questions are these, 1)where and how do you pick up the millivolt readings? 2)Is there a picture anywhere? 3) I have a fluke meter with only one voltage setting, will that be accurate enough?

Secondly, the mechanic states that under no conditions should I attempt to adjust the TPS on an '04 V11, he claims that it is very very difficult to bring it back to factory specs if I mess it up.

 

Thanks guys (and ladies!)

 

Look in the How To section. You will find a condensed thread on TPS setup with pictures right near the top. To monitor the voltage at the throttle body, I use two short lengths of thin stranded wire of about 30 gauge. Disconnect the TPS cable. Strip about 1/4-3/8 insulation off the ends of the stranded wires, insert a stripped end into the connector, and push the connector in part way, far enough to make electrical connection, but no need to jam it all the way.

 

It isn't difficult to move the TPS to adjust the TPS voltage. The trick is that it moves a bit as you tighten the screw down again, so a little "Kentucky Windage" has to be used to get it right. It's no big deal. A couple of trial and error attempts will do the trick. A voltmeter with readings to 0.5XX volts DC is best (three digits below the decimal on a 0.5 volt reading). If you want to cover yourself, measure the voltage before you make any adjustment, so you know where it was originally, in case you want to return it to where it was. It is worth the effort. My factory calibrated '04 was quite a bit off even when it was new, and the throttle synch procedure is easy. My bike ran better, and fuel economy jumped up from 38 to 42 MPG.

[dlaing]

I spliced and soldered in a couple of wires just to make taking readings easier.

(But Ryland's suggestion probably works great. I never thought of that!)

I should take a photo of which wires to probe and add it to the pinned TPS post.....and I would have if I could remember which wires I soldered to.

[Mike Stewart]

Hello,

 

Just measure your tps voltage before you mess with it and write down the reading, at least you can go back to where it was if you run into any problems. Most bikes run well with a tps voltage of .5 volts. Not sure if your Fluke goes down low enough. I believe Doc has the right tps wire colors and my 03 Rosso is in the pics. It is not too hard to adjust, you just need some patients. Ohh yeah, make sure your fast idle lever is all the way off when you check the reading!

 

Mike

 

 

 

Hi all, I've read much of the TPS thread and still have a question as well as a comment from a Guzzi mechanic.

My questions are these, 1)where and how do you pick up the millivolt readings? 2)Is there a picture anywhere? 3) I have a fluke meter with only one voltage setting, will that be accurate enough?

Secondly, the mechanic states that under no conditions should I attempt to adjust the TPS on an '04 V11, he claims that it is very very difficult to bring it back to factory specs if I mess it up.

 

Thanks guys (and ladies!)

[savagehenry]

...One of the last "Dark Areas" of this NEW bike thing. 23 years riding, my Nero is a 26 year jump in motorcycling for me. All this talk of new fangled teknowledgy has me almost ready to start diggin" in myself...Lord help me, you bastards... , It's all your fault, S.H.

[docc]

...One of the last "Dark Areas" of this NEW bike thing. 23 years riding, my Nero is a 26 year jump in motorcycling for me. All this talk of new fangled teknowledgy has me almost ready to start diggin" in myself...Lord help me, you bastards... , It's all your fault, S.H.

 

You're on the slippery slope now. Soon you'll be 'tweaking your map' and using synthetic oil.

 

Now if we can get you to stop casting pistons in the sand . . .

[cycdude6]

Ok, thanks everyone....what I'm hearing is I should try and insert something into the connection at the tps, into the white violet and violet wires, and get the readings there. 150mv with fully closed butterflies, key on, bike not running. Right?

What is more important, 150mv key on, bike off or 485mv, bike at stable idle?

 

Thanks again,

John

[docc]

Right. 150mV (+/-) bike off, key on, linkage off, fast idle mechanism defeated.

 

485 (to 525) mV running at a stable idle.*

 

 

* How you atone for the stable idle is a question of semantics, technical procedure and theology. Oh, and imbibition.

[Ryland3210]

Right. 150mV (+/-) bike off, key on, linkage off, fast idle mechanism defeated.

 

* How you atone for the stable idle is a question of semantics, technical procedure and theology. Oh, and imbibition.

 

AND back off the right throttle body's idle screw to ensure the butterfly is fully closed, AND adjust the fast idle mechanism if it does not let the butterfly close completely. Beware of piecemeal instructions. Best follow the proven instructions in the How to Section to the letter to leave nothing to chance. :!:

[Mike Stewart]

OK,

 

Just to make things more simple.......You don't have to go through the pain of disconnecting the throttle linkages and backing out the idle stop screw to make the base 150mv reading on the TPS sensor. This was what we did before everyone went with (or figured out) the 500mv (.5 volt) setting with the throttle closed at idle (fast idle lever fully off). In the real world (on cars) it does not matter if you adjust the tps with just the key on or running. Motorcycles seem to be somewhat more funky with the charging system and electrics in general, so warm at idle seems to be the key.

 

And, you should check the tps voltage after you sync your throttle bodies and adjust your idle!

 

Just trying to make things more clear for everyone.

 

Mike

 

 

 

 

Ok, thanks everyone....what I'm hearing is I should try and insert something into the connection at the tps, into the white violet and violet wires, and get the readings there. 150mv with fully closed butterflies, key on, bike not running. Right?

What is more important, 150mv key on, bike off or 485mv, bike at stable idle?

 

Thanks again,

John

[docc]

AND back off the right throttle body's idle screw to ensure the butterfly is fully closed, AND adjust the fast idle mechanism if it does not let the butterfly close completely. Beware of piecemeal instructions. Best follow the proven instructions in the How to Section to the letter to leave nothing to chance. :!:

I knew there was at least one other thing . . .

 

Actually this is how we ended up with a pinned thread with as complete a procedure as possible. Many have gotten by with less (my dealer included), but the more complete the procedure, the more reliable the result.

[Ryland3210]

OK,

 

Just to make things more simple.......You don't have to go through the pain of disconnecting the throttle linkages and backing out the idle stop screw to make the base 150mv reading on the TPS sensor. This was what we did before everyone went with (or figured out) the 500mv (.5 volt) setting with the throttle closed at idle (fast idle lever fully off). In the real world (on cars) it does not matter if you adjust the tps with just the key on or running. Motorcycles seem to be somewhat more funky with the charging system and electrics in general, so warm at idle seems to be the key.

 

And, you should check the tps voltage after you sync your throttle bodies and adjust your idle!

 

Just trying to make things more clear for everyone.

 

Mike

 

Mike, with due respect, although what you suggest may be simpler, it runs the risk of leaving errors in TPS calibration untouched. Once the carefully considered and scientifically developed procedure is done, future adjustments can be made very easily. However, my own experience shows that factory calibration can be far off. Had I taken the shortcut you suggest, I'd still be burning 10% more fuel with the shorter cruise range as well.

 

Warm at idle was not found necessary for TPS calibration. That can be done cold. Having the engine warm for throttle sych is worthwhile.

[Mike Stewart]

I have done the long draw out base tps adjustment on my 2000 V11 Sport, with the Raceco valve lash specs the idle speed needed to be turned down. Thus changing the tps voltage which was a low 270mv. I was using a Powercommander and all of the maps I had tried did not work well with this bike. I finally came up with a map that worked well and then after going to Todd Eagans Powercommander seminar at a Guzzi rally, I realized that the maps I was getting were based on the 500mv tps setting. The real moral to the story is, if your bike runs good, don't mess with it. My 03 Rosso runs great with a tps voltage of 466mv. and I would not change it.

 

I agree that a warm engine is not needed, I was only suggesting that so the fast idle lever would be fully off.

 

Mike

 

 

Mike, with due respect, although what you suggest may be simpler, it runs the risk of leaving errors in TPS calibration untouched. Once the carefully considered and scientifically developed procedure is done, future adjustments can be made very easily. However, my own experience shows that factory calibration can be far off. Had I taken the shortcut you suggest, I'd still be burning 10% more fuel with the shorter cruise range as well.

 

Warm at idle was not found necessary for TPS calibration. That can be done cold. Having the engine warm for throttle sych is worthwhile.