TPS adjust/TB balance/air bleed screws

[Tom M]

A couple questions: Should I care that my TPS is around 440mV when idling about 1150rpm with air bypass screws about 1/2 turn out or less? Could "coughing" between 3k and 4krpm be due to air bleeds that are less than 1/2 turn open, or is this purely a TB balance issue?

 

Background: Last month I adjusted my valve lash to .006/.008" and reset the TPS base voltage at 150mV with the linkage disconnected and the right side idle stop backed all the way off. With the air bleeds completely closed and the idle TPS voltage to set to 520mV idle rpm is way too high. I tried running with the bypass screws closed and the idle backed down to ~1150 rpm/480mV, got lots of low throttle coughing. Since opening the bypass screws a bit and backing down the idle stop to 1100rpm/440mV I'm still getting an occasional cough at low throttle openings between 3k and 4k rpm, but otherwise the bike seems to be running well. I've tried to balance the TBs to a happy medium between perfect balance at idle and perfect balance at 3000rpm. Also tried some on-road balance adjustment as Ouiji has done but still can't get rid of the occasional cough. I know I could open the air bleeds more, but then I'll have to back off the idle stop even more dropping my TPS setting even farther away from the 520mV target. No apparent air leaks and the bike did not have this cough before I did my winter "tune up" . Oh yeah, plugs are new.

 

Any suggestions on improvements from here are welcome.

 

edit: I originally posted valves set to .004/.006, I actually set them to .006/.008.

[raz]

My personal take, without hesitation, is to rather keep the base 150 mV than the idle setting (if can't have both). My reasoning is at higher rpms, the computer will then have a correct picture of how much throttle is applied.

 

So the way I read it, the higher setting is more a help for you to find the correct idle, than a setting for the computer to worry about.

[Mr. Bean]

I had the same problem you have...I was constantly chasing one setting or the other trying to get everything close but never could get the bike to run the way it should using the settings from the book.

 

I know it goes against the method pinned on this site for how to set the tuning settings but may I suggest you try something completely different? I learned the following method from Micha at Moto International.

 

Step one - Set your valves to world settings

Step two - Set your bleed screws to open 1 full turn

Step three - Synch throttle bodies at just off idle (around 1800 rpm)

Step four - Set idle to 1100 using left idle screw adjuster only

Step five - Set TPS to 3.6 degrees (I forget what that translates to in mv..someone here will know)

Step six - Ensure idle trim is set to zero

 

These settings made my bike run like I expect the factory wanted it to run. No more coughing, excessive vibrations at speed, or unstable idle speeds. It honestly was like night and day!

 

Randy

[Guest frankdugo]

i'll second that3.6 deg. setting.thanks to w o for that one.

[dlaing]

As one of the authors of the method posted here:

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

I have agreed with Raz to keep the base 150mV reading, but it seems like many people are getting too high of an idle when they set it to the 521mV that we recommended.

3.6° is supposed to correspond to 525mV according to MPH's chart, so you could use 3.6° as it is certainly close enough.

But the fact that people that set to 150mV and then 521mV are getting too high of an idle seems to indicate one of two likely possibilities.

The first and in my opinion, most likely possibility, is that they are not backing the butterfly valve off all the the way. Perhaps it is getting hung on the "choke". Or perhaps it is getting hung on carbon build up????

The second most likely possibility as that our bikes differ greatly from one another, and that the idle TPS setting is more important. If that is the case it will invalidate the instructions we wrote.

Logically it makes sense that the throttle bodies are precisely bored and that the baseline should be made at the more absolute fully closed position rather than a vague point determined at idle subject to variations of flow, etc. Using the inaccurate Guzzi Tach and that method throws accuracy further to the fate of luck..

But the ECU is looking for its baseline at idle, so there is some basis for Micha's method that seems to value the idle reading above the base reading.

In any case if you do what Mr. Bean and Micha suggest, you will run richer, which will generally be smoother and more forgiving.

So, apparent success from the method may still not be ideal, as you may now be too rich, or maybe not????

If you give Micha's method a try, which at this point I recommend unless you feel like giving the base TPS setting a second attempt, would you please note and report the before and after Wide Open Throttle TPS Voltage reading? Thanks in advance My suspicion is that you will probably get a current reading below 4.80V and then after the Micha method it will be 4.85V or higher. If I am not correct and you jump from say 4.86 to above 4.9 something, then I suspect something much more complex than I understand is happening. Like maybe your bike just breathes really well, and needs a higher TPS to ensure proper fuel mixture.

But then again, volt meter accuracy at that voltage could render my recommended test useless....

Sorry for the long speculative post that may not be clear as I am tired. Maybe Ryland can straighten out my errors and add clearer insight.

It would be good to get to the bottom of why the posted method did not work for Mr. Bean, or you.

The Ti muffler owners have another challenge, but understanding this may help understand the Ti muffler setup.

Best of luck!

[motoguzznix]

A couple questions: Should I care that my TPS is around 440mV when idling about 1150rpm with air bypass screws about 1/2 turn out or less? Could "coughing" between 3k and 4krpm be due to air bleeds that are less than 1/2 turn open, or is this purely a TB balance issue?

 

Background: Last month I adjusted my valve lash to .004/.006" and reset the TPS base voltage at 150mV with the linkage disconnected and the right side idle stop backed all the way off. With the air bleeds completely closed and the idle TPS voltage to set to 520mV idle rpm is way too high. I tried running with the bypass screws closed and the idle backed down to ~1150 rpm/480mV, got lots of low throttle coughing. Since opening the bypass screws a bit and backing down the idle stop to 1100rpm/440mV I'm still getting an occasional cough at low throttle openings between 3k and 4k rpm, but otherwise the bike seems to be running well. I've tried to balance the TBs to a happy medium between perfect balance at idle and perfect balance at 3000rpm. Also tried some on-road balance adjustment as Ouiji has done but still can't get rid of the occasional cough. I know I could open the air bleeds more, but then I'll have to back off the idle stop even more dropping my TPS setting even farther away from the 520mV target. No apparent air leaks and the bike did not have this cough before I did my winter "tune up" . Oh yeah, plugs are new.

 

Any suggestions on improvements from here are welcome.

Tom

 

The 520 mV setting is for the earlier bikes KR and KS. Later bikes should have 460 mV and you are pretty close to this.

I agree not to change the 150 mV closed setting.

Setting your valves to 0,008/0,010 might lower the idle speed slightly that you can raise the throttle setting to 460 mV. This should prevent the coughing.

[Mr. Bean]

The first and in my opinion, most likely possibility, is that they are not backing the butterfly valve off all the the way. Perhaps it is getting hung on the "choke". Or perhaps it is getting hung on carbon build up????

The second most likely possibility as that our bikes differ greatly from one another, and that the idle TPS setting is more important.

 

After trying different things I assumed this was the case on my bike as well. I went so far as to slip the boot off the TB and look to make sure it was closed. It was actually very clean, just some oil buildup that I wiped off and the choke wasn't interfering. (I completely disengaged it.)

 

Not sure if my bike is just a unique "Monday" bike or what...but the behavior I was getting was as follows:

 

If I set the TPS to 150 with throttle closed and everything disconnected, and the bleeds open 1/2 turn, I would have to set my idle to 2.6 degrees to keep 1050 to 1100 rpm at idle. This resulted in a very "rough" take off from a stop and poor idling speed variation with temperature. It was difficult to ride the bike in commuting traffic. The bike also was very buzzy at higher RPMs. (A "buzziness" that I could not get rid off with synch adjustments) I also got a lot of pinging north of 4000 RPM. If I adjusted the TPS to 3.4 to 3.6 degrees, I had to completely close the bleed screws in order to obtain a 1100 rpm idle. The bike ran better at higher RPMs but was even worse taking off from a stop or at low RPMs and the idle speed was even more varied with temperature. My mileage with these settings varied from the low to mid 30's.

 

With the settings recommended by MI, I find I have a very stable idle speed in all weather conditions, the bike is very easy to ride smoothly in slow traffic and there are no more hiccups in the 3000 rpm range. I also don't get near as much pinging anymore...now it just limited to really whacking open the throttle in the 3500 to 4000 rpm range (something I probably shouldn't do anyway! ) The bike is also much smoother in the higher RPM ranges...not nearly as buzzy. What is curious is that this all sounds as if it is running much richer. What is odd is that my plugs are cleaner and my mileage is up to the high 30's now in my normal mixed commute riding.

 

I hate to mess with it now that it is running so well, but is there an easy way to test the TPS? I can't think of any other component that could cause the variations that I get besides the TPS.

 

Randy

[Greg Field]

I have personally seen Micha's method transform several bikes that the owners of which couldn't make run right any other way. I use it. Works great. Mine's a later bike with the front crossover. So's Mr. Beans. So's the bike his method made the biggest difference on (a Coppa Itali owned by a mechanic who tried everything else to get it to run right and then just sold it because he couldn't figure it out).

 

We here are all amateurs, so far as I know. Micha has worked professionally on V11 Sports almost daily since the very first one to enter the US was sold through Moto I. He's learned a thing or two in that time.

[Tom M]

Thanks for the input guys.

 

Randy, is your step 6 "ensure idle trim is set to zero" referring to the the ECU or a Power Commander? I verified the PCIII saw closed throttle as 0%, don't have the capability to check the ECU.

 

Dave, I'm pretty sure I had the right side stop screw all the way out and no high idle cam contact when I reset the TPS, but I'll check it again. I think the 0 degree TPS reading was around 190mV before I reset to 150. I also think my idle TPS was around 490mV (key on, engine off) before I started messing with it. I didn't check the wide open throttle setting, will do that when I get back at it. Also, I get higher TPS readings with the engine running than when it's off. Are the values in the how-to article taken with the engine running or off? You should know that I'm running the stock ECU with the factory Ti pipes, not the "race" ECU.

 

Ernst, I have a 2002 which didn't have the crossover at the alternator here in the US, so I think my bike falls into the older model category. I have both the older MG shop manual and the updated one. There's no section for setting the idle/TPS in the older manual that I have, but the newer one for a catylized engine says to set the throttle plate to 3.8 +/-.1 degrees at idle, which is .553mV on the chart in the how-to article here. Where did you see the 460mV figure?

 

What I'm really unclear on is whether the ECU equates a completely closed throttle plate to 150mV, or if it equates idle with 3.x degree throttle opening/525mV. Getting both settings correct would be great but I can't do it on my bike. The bike does run well now except for the occasional low throttle cough.

 

Thanks again and please keep the suggestions coming.

[Mr. Bean]

Thanks for the input guys.

 

Randy, is your step 6 "ensure idle trim is set to zero" referring to the the ECU or a Power Commander? I verified the PCIII saw closed throttle as 0%, don't have the capability to check the ECU.

 

Tom,

 

The idle trim requires the use of the VDSTS software or I assume an Axone would work as well. If you have a dealer close by, it should not cost too much to just have them set it. Or maybe someone else close by has the software? You can get it from Guzzitech as well...not too expensive compared to other accessories or tools and I think it is indespensible.

 

Randy

[Tom M]

I have personally seen Micha's method transform several bikes that the owners of which couldn't make run right any other way. I use it. Works great. Mine's a later bike with the front crossover. So's Mr. Beans. So's the bike his method made the biggest difference on (a Coppa Itali owned by a mechanic who tried everything else to get it to run right and then just sold it because he couldn't figure it out).

 

We here are all amateurs, so far as I know. Micha has worked professionally on V11 Sports almost daily since the very first one to enter the US was sold through Moto I. He's learned a thing or two in that time.

 

Greg, Do you know if he's uses this exact method on the pre-04 bikes with no front crossover?

 

PS I am not an amateur, I'm more like a gorilla with a screwdriver.

[Greg Field]

I'll ask him, just to be sure.

[dlaing]

Dave, I'm pretty sure I had the right side stop screw all the way out and no high idle cam contact when I reset the TPS, but I'll check it again. I think the 0 degree TPS reading was around 190mV before I reset to 150. I also think my idle TPS was around 490mV (key on, engine off) before I started messing with it. I didn't check the wide open throttle setting, will do that when I get back at it. Also, I get higher TPS readings with the engine running than when it's off. Are the values in the how-to article taken with the engine running or off? You should know that I'm running the stock ECU with the factory Ti pipes, not the "race" ECU.

What? No power commander?!? Then you will likely benefit from increased TPS millivolts.

The 150mV reading is done with engine not running. (technically debatable, but it is too tricky to run the engine on one cylinder)

The 521mV reading is done with engine running (because it can be done easily and reflects real running conditions better)

 

What I'm really unclear on is whether the ECU equates a completely closed throttle plate to 150mV, or if it equates idle with 3.x degree throttle opening/525mV. Getting both settings correct would be great but I can't do it on my bike. The bike does run well now except for the occasional low throttle cough.

I am unclear, too.

Micha has probably tuned more V11s than anyone on Earth save a few factory assembly guys, so there is little doubt he knows how to get it right.

But I don't believe that it is right to throw away the 150mV setting, except for a little fudging room.

Your mufflers combined presumably with no PCIII will want some fudging, and clearly Micha's method will work better for you, so unless you get a PCIII, I would go with his method.

One thing that both of the methods don't take into consideration, is what has been done to the trim level in the ECU using the Axeone or VDSTS.

The factory sets the trim to pass emissions.

Many shops set the trim richer.

My mechanic set mine richer, then I had him set it back (not sure if that was zero) when I went for dyno mapping so that it would be a more useful base map for repeatable results.

I suspect that the trim level is messing up quite a few bikes. Also we generally find the bike runs better with a higher TPS number because the factory mapping isn't perfect and is generally too lean.

I forget what Mr. Bean's details are.

Was the bike completely stock?

[dlaing]

I'll ask him, just to be sure.

Also, if you could ask him if he uses different numbers for the Ti ECU bikes, and the variations with or without front cross over bikes, that would be appreciated.

[Mr. Bean]

I forget what Mr. Bean's details are.

Was the bike completely stock?

 

The bike was a stock Ballabio when I first tried his tuning method. Now it has a Mistral crossover on it, otherwise it is still a stock drivetrain. I used the same tuning procedure both before and after with the same excellent results. I have not noticed any substantial change with the new crossover, just some better sound, better torque, same mileage.

 

Randy