Throttle balancing and TPS resetting

[GrahamNZ]

This will be new to some and old hat to others, but given recent events.............here it is again with an important extra.

General arrangement
• The left throttle body carries the throttle-stop screw, - the "sacred screw" - which is factory set and must not be altered. It sets the left throttle butterfly mechanically at a base position of 4.5º to 4.9º with the throttle closed and the engine stopped. 4.5 seems to be the common setting.
• The right throttle spindle carries the TPS which must be zeroed electonically
• whenever throttle balance is adjusted. The TPS should also read 4.5º to 4.9º with the throttle closed and the engine stopped.
• An Axone device with software 5.0.4 or later (or TechnoResearch VDSTS) is needed for the ECU type IAW5AM to set the TPS zero position of the adjustable right throttle to agree with the non-adjustable left throttle.
• Idling speed and mixture are dealt with automatically by an ECU-controlled stepper-motor and cannot be adjusted manually.
• Both throttle bodies have air bleed screws which act independently of the ECU and are used only to perfect idling vacuum. Both screws should be closed or just one slightly open.

TPS resetting
• Connect the Axone or VDSTS to the diagnostic plug provided in front of the tool kit compartment, and to the battery terminals, and turn the Axone or VDSTS on. Turn on the ignition key and within 10 seconds connect the Axone or VDSTS to the ECU. If the TPS reading is not 4.5º to 4.9º select and run the TPS resetting function on the Axone or VDSTS.
• When prompted to do so, turn off the key for at least 30 seconds. When the key is turned on again the TPS reading should be 4.5º to 4.9º

Throttle balancing
• Start the engine and warm to 60 degrees C and then stop it.
• Remove the M6 blanking screws on the outer sides of both throttle bodies and fit vacuum hose nipples. Connect vacuum gauge hoses to the nipples and close both throttle-body air-bleed screws so any vacuum balancing won’t be influenced by the air bleeds.
• Start the engine and gradually increase the speed to a steady 3,000 RPM. If the vacuum readings at 3,000 RPM are not within 1cm Hg of each other the balance will need to be adjusted and the TPS reset again.
• Vacuum balance is adjusted using the adjusting screw on the left end of the link rod. The rod length should not be altered by moving the ball joint ends because that can affect the parallel movement of the throttle levers and give unequal opening as the throttles are opened further.
• Stop the engine and re-run the Axone or VDSTS TPS resetting procedure. This is essential because any adjustment of the link rod will have moved the TPS position at the same time. The Axone or VDSTS then tells the TPS to treat its physical position as being base in relation to the mechanically-stopped left throttle.
• Start the engine and at idle fine-tune the Hg balance by opening only the air bleed on the side with the lower Hg reading.

Now the extra bit for those of us who have a tampered with "sacred screw".
Resetting the sacred throttle stop screw

Here is a method of resetting that "sacred screw". One of us had suffered from total dealer mechanic incompetence where the sacred screw and the air bypass screws had been used to try to tune the bike - unsuccessfully of course. The adjuster on the left end of the the throttle link rod had never been touched, nor had the ball joints on the rod ends been touched. The cure was this:

• Using Axone or VDSTS reset the TPS as above.
• Close both air bypass screws.
• Using a vacuum gauge set, balance the vacuum at 2,500 - 3,000rpm as above.
• Reset the TPS again.
• Use the air bypass screws to balance the idling vacuum. (RH screw closed - LH slightly open)
• The idling speed was now too high but the bike otherwise throttled well. To cure that, the sacred screw was backed off to produce 1100rpm idling, another TPS reset was done and finally the air bypass screw balance was perfected.

Quite simple really. Maybe not the perfect method but one that works in the real world because now that bike throttles perfectly.

Graham

 

[GrahamNZ]

This lot from a former forum???? may be of interest to home tuners.

Breva V1100 tuning update

"Having just awoken from a long sleep and having had nothing new to say for a while, maybe it’s time to bore you all with a few developments.

Until fairly recently I’ve been blessed with access to a competent mechanic armed with an Axone. Sadly that has all changed so it’s become time to be fully self-reliant for tuning my Breva.

Vacuum balancing gauge
The first step was to construct a manometer (vaccum gauge). “Why bother?” I hear you ask. Well, I used to have a mercury tube gauge but it went the way of many fragile things and a replacement wasn’t available here. (Mercury is harmful to health you know!) The twin-dial gauge types I’ve always found harder to use than watching a couple of adjacent parallel vertical columns. A manometer using oil also is much more sensitive than mercury. (1cm Hg = ?cm of 15W oil?) Dunno, but the vaccum needed to alter the oil a given height is a lot less than that required for mercury.

(There was a photo here but the system I used to use - photobucket.com - won't work for me anymore here?????)

Materials I used:
5mm bore, high quality, fuel and oil resistant clear tubing. 6m length.
2mm bore clear silicone tubing as used for model engine fuel line. 15cm length.
Saddle clips as used to secure electrical cables.
Tee union from an old Scottoiler kit.
Screws to plug the ends of the silicone tubing.
M6 screw-in take-off nipples, also from an old Scottoiler kit. 2 off.
Strip of wood about 40mm x 18mm x 900mm, painted white.
Small volume of 15W fork oil.
A means of hanging the gauge above the bike when in use.

The tee at the bottom of the loop allows the oil to be added using a syringe.
A short length of silicone tubing is used to connect onto the take-off nipples, which get very hot when the engine is running.
The clear tubing needs to have ends of exactly equal length.

(I’ve posted earlier the procedure for balancing the throttles.)


TechnoResearch VDSTS
I purchased a VDSTS kit from Todd with cables for both laptop and PDA use. While a PDA is OK, the programme is much more user-friendly and fun to watch when used on a laptop. I guess the screen on a laptop is bigger and allows space for prompts and warning messages. Probably I’m a bit dim, but I didn’t find the instructions as easy to follow as I needed so after serveral uses of the programme I made the following notes for myself:

VDSTS on laptop for Breva
The standard cable supplied with VDSTS is for connection to a laptop 9-pin serial port. A Keyspan serial to USB cable can also be used if the laptop has only a USB port. That cable needs the software driver supplied on a CD with the cable to be installed in order to function.

Install VDSTS from the VDSTS CD. Open the progression of relevant VDSTS folders and subfolders and then the one for XP or whatever operating system your PC has. Open it and click the setup icon to install VDSTS.

Once installed, use the desktop icon to launch VDSTS.

On the first window to appear press the English language button.

On the next screen to appear click on the Communication tab at the screen top and from the drop-down menu click Port Setting. A window will appear and at the top of it a panel labelled VDST with up/down arrows beside it. Move through to choose the appropriate Com port you are to connect through and click OK. Unless you know the Com port number you may need to re-visit this to get connection to the bike.

With the cables connected to the bike and laptop and the kill switch on Run, turn on the ignition and click the bike icon button (Brand/Ecu/Model) and then VDSTS will automatically search for and identify the Ecu type and show the type on the screen bottom. For Breva MM IAW5AM. A window will appear indicating the Ecu type found and asking you to confirm if that is correct.

Now press the HotSync button to connect VDSTS to the Ecu. Once connection is confirmed, all the buttons along the top of the screen will become active.

Press the dials button (Gauges/Meters) to display data including the TPS reading. Open the throttle progressively and the TPS reading should respond accordingly. For Breva 4.5ºto 4.9º with closed throttle and 84.2º to 84.5º fully open.

NB The Breva has the left throttle plate factory set at 4.6º and the idle stop screw (the "sacred screw) on the left throttle body must not be touched at all.

To reset the TPS, press the screwdriver icon (Active Settings) and then select TPS from the tabs towards the screen top. That will take VDSTS to two windows where resetting the TPS are dealt with but only the left window is active. Press the TPS/screwdriver button and a warning will come up that resetting the TPS will affect the engine operation. Press OK and to the right of the screwdriver icon a seconds count down will appear and when finished Pass should appear together with an ECU Reset window. This window will invite you to turn the ignition off for a minimum of 13 seconds and then to turn the ignition on again. When done, press OK.

Return to the Gauges/Meters screen and the reset TPS reading will show. In the case of the Breva that should be 4.5ºto 4.9º At this stage the Breva TPS resetting is done but you can go on to check the function of many components by going to the icon which looks like a fuel injector (Active Test) and then activating the various options presented to you. All quite fun really.

And the result?
Hand-on-heart I can honestly say that now the bike throttles better than it ever has. So good that I’d rate it as being up with the best FI bikes I’ve ridden. So good that sometimes I tend to forget to change gears when cruising on winding roads because the bike will pull happily from as low as 2,000rpm without complaint and the off-on transition is all but seamless. Apart from being careful throughout the tuning procedure, more than anything the very fine vacuum balance achievable using the oil-filled manometer I believe brought the biggest benefit. These bikes really do like the vacuum balance to be as accurate as possible."

Rider to the above
Having trolled through the posts made while I was unable to access this site, I noted a question about how often the vacuum balance and TPS resetting should be done. Anything which affects the volumetric efficiency of a cylinder is reason to go through a re-tuning procedure. Eg. Adjusting the tappets. Wear on the engine. A different exhaust. Guzzis are long-term ownership bikes - let's face it they're great bikes but not everyone appreciates that so they can be difficult to sell - so the expense of getting your own VDSTS, laptop, and a good vacuum tool, and the expertise to use them, are a sound investment. Fun too.

Graham

 

[GrahamNZ]

The missing manometer photo - thanks MikeC.

Graham

 

[MurphyPeoples]

Graham-
I just printed this post out to go into my MG Repair Book I'm making.

Now.... for the BIG question....

is the CD-ROM and Programme MacIntosh compatible???
We're a Mac family. If it is I need to get in touch with Todd and spend some money!
Murphy

 

[NeroGuzzi]

MurphyPeoples wrote:

Now.... for the BIG question....

is the CD-ROM and Programme MacIntosh compatible???
We're a Mac family. If it is I need to get in touch with Todd and spend some money!
Murphy

It is PC compatible only. Have you thought about using bootcamp and installing windows on a partition? I use a MAC, but also have an ancient PC laptop to run VDSTS.

 

[Holt]

Graham;

Most splendid written manual!

-But how on earth do you suspect us to be owners of old scottoilers? :laugh:

 

[GrahamNZ]

Holt

Is there anyone anywhere who's mature enough to own a Guzzi who hasn't progressed through chain-driven bikes? Is there anyone anywhere who's owned chain-driven bikes who hasn't realised that a Scottoiler is the only solution until a shaftie or belter is progressed to?

Seriously though, any decent sized bike shop will have a bucket of those Scottoiler bits which they don't need.

Graham

 

[Brian UK]

GrahamNZ wrote:

Is there anyone anywhere who's owned chain-driven bikes who hasn't realised that a Scottoiler is the only solution until a shaftie or belter is progressed to?

Yes, I had a Commando way back, and that had its own chain oiler built in, which did sort of work.

 

[Griso Guy]

Hi Gram,
It seems that you live NZ. Correct? Anyway, I assume you own a manometer for resetting the tb's? Would you happen to remember the cost of the unit and where can why purchase one?
Thanks.

Doug

 

[john zibell]

Griso Guy wrote:

Hi Gram,
It seems that you live NZ. Correct? Anyway, I assume you own a manometer for resetting the tb's? Would you happen to remember the cost of the unit and where can why purchase one?
Thanks.

Doug

Doug,

Graham made his own. You can purchase a twin max, to carb sticks.

Twin Max http://www.twinmax.co.uk/ or here http://www.adventuremotogear.com/twinmax-p-28.html

Carb sticks http://www.motodepot.com/product_detail ... 7&sku=3715

or make your own http://www.obairlann.net/reaper/motorcy ... meter.html

 

[Holt]

GrahamNZ wrote:

Holt

Is there anyone anywhere who's mature enough to own a Guzzi who hasn't progressed through chain-driven bikes? Is there anyone anywhere who's owned chain-driven bikes who hasn't realised that a Scottoiler is the only solution until a shaftie or belter is progressed to?

Seriously though, any decent sized bike shop will have a bucket of those Scottoiler bits which they don't need.

Graham

Well;

I sold my latest - last? - chain-driven bike back in 1982 (?). Don't remember Scottoilers then. Hardly o-ring chains either. :laugh:

 

[Joe breva1100]

Cheers Graham, as is so often the case the above post is very usefull and informative.

I can't see myself buying a VDSTS, I probably continue to do most of the service myself before taking the bike to a Guzzi dealer for the Axone treatment, (which I only tend to do every other service), but it is good to find out what its all about.

Cheers
JB

 

[sn0winSaskatoon]

This is really great stuff, thank you so much Graham in New Zealand.

I might be imagining it, but were there some photos posted to the forum identifying all the various wee bits... Perhaps I'm dense, but the photos in the pdf manuals aren't terribly good - and I'm a noob with FI (I miss carburettors).

Breva had her first road trip and now has 2500 km on the clock! But it's 0 degrees C again this morning!

Ian

 

[GrahamNZ]

Ian
No photos of the bits on the bike, sorry. Only photo was of the home-made oil-filled manometer. I thought the photos in the manual were OK. Pretty cold here now, by our standards, but aren't you in early summer?

Joe
I went the VDSTS way only when the dealer I used and who had an Axone, went out of business. Glad I did because I prefer to be self-reliant as much as possible. VDSTS, with different cables, is used on Buells too. IMHO setting the TPS every second maintenance session should be fine provided the bike seems to be running well.

 

[Roblatt]

Pardon my ignorance but what's the difference between Axone and VDSTS. Can the later do all the thins the former does?
I only ask because I'm starting to think about buying a VDSTS.

thanks

Robert

 

[GrahamNZ]

Robert

VDSTS works well for the home mechanic - and others - for performing maintenance tasks including TPS setting and electronic component testing. The one thing an Axone alone can do is obtain any ECU mapping updates and install them into your bike.

As far as I'm aware there was a mapping update issued for the very early Brevas, like mine. Maybe some also for other models that I'm not aware of.

VDSTS is great value IMHO. I use it for both my bikes. On the Breva it works for me on a laptop PC with XP using both serial and USB ports. USB needs the extra cable TechnoResearch offer. On the Buell only, in works on PC and PDA, but I could never get the PDA to make connection to the Breva.

 

[Roblatt]

thanks Graham.

It's clear now.

 

[Petrov]

I have a motion Pro carb balancer. Do you have any idea how to hook up the vacuum hoses? Do I need special fittings?

 

[john zibell]

I have a motion Pro carb balancer. Do you have any idea how to hook up the vacuum hoses? Do I need special fittings?

If we know the bike, and what country you live in it would help. If the Breva/Norge/Sport in the US, then no. If in another country you would need adapters that screw into the manifolds for the vacuum hoses to make a connection.

If you are asking how to connect the tool, I suggest you find someone who knows how to use it. It is better to learn first hand from a knowledgeable person as internet descriptions are open to interpretation. Also do you have the needed software to reset the TPS?

 

[Petrov]

Its a Norge 1200 here in US. I am picking up the bike in 2 days, I am planning ahead and doing research.
Yes I will be buying the software to reset TPS and do other stuff.