need some help with VDST

[booger]

Specifically, AFV, Fuel Trim, and Idle Speed adjustments. I haven't messed with those as I just set the TPS and throttle synced, called it good, and went riding. However I just got a exhaust gas analyzer and would like to tune more thoroughly. Bike idles at 1000rpm and I need to get it idling higher. Plugs have a whitish powdery coating. I understand that's a little on the lean side. From my understanding I want a brownish powdery coating. Shop manual says I need to tune the CO to +-5%. All I need is a walkthrough on the software. Also - should I probe both exhaust pipes, and can I set fueling in each cylinder individually with VDST, or are the settings for both cylinders? thanks

[scott_araujo]

Year?  Model?

[booger]

I have a 2006 S2R800 with 5AM ECU -

What are the operations required in the software to perform the adjustments(navigating the application)? Are all adjustments done in the Active Settings tab? I'm assuming the adjustments are made with the bike running.

[scott_araujo]

Ok, I've got an '03 800 Dark so I think it's the exact same engine.  There are two things you need to do with the ignition on, one with the engine running one with it stopped.

TPS Reset:
This needs to be done with the ignition turned on but the engine NOT running.  If it's running it can suck the butterflies open and that's bad, you want them still and totally closed.  If you just turn the ignition on that's not good enough, the ECU will go to sleep in a few minutes and you can't connect to it with VDSTS. So...

Start the bike and get it running.  Connect VDSTS so you know it's working.  Leave the key where it is but kill the engine with the rocker cutoff switch.  Once it stops running turn the switch back on.  Now open the throttle and let it snap shut.  Do this three times in a row.  This makes sure the throttle butterflies are totally seated.  Now in VDSTS under 'Active Settings' (blue screwdriver button) go to 'TPS Reset' tab.  Press it.  It will take a few seconds and then it is reset.

Small note, do not unscrew your TPS or attempt to measure or adjust the voltage.  You have a non-linear TPS and the only thing you need to do to reset it is what you just did.

Fuel trim/CO trim:
The other thing you need to do is adjust the fuel trim, also called the idle CO trim and basically the electronic equivalent of an idle mixture screw on a carburetor.  This is also under 'Active Settings' (blue screwdriver button) on the 'Fuel Trim' tab.  The bike should be running and up to operating temperature when you do this.  Going from memory here since I'm not plugged in, you have to hit a button to read the current setting.  It will take a few seconds and then display.  You have a range of -128 to +127.  It probably won't run with it set more than +/-30.  You can type in the value or use the up and down arrows.  I suggest the arrows.  If you put in a radically different value it could be too rich or lean and the bike could stop running.  Then you have to try to get connected without the bike running to reset it to something viable.  This is a pain, ask me how I know   Anyway, you can move the setting up or down.  Make small changes and listen to the bike run.  Basically the idea is to go richer bit by bit, the engine speed should increase ever so slightly.  Go slowly, a notch or two, let it settle for a few seconds, notch or two, settle, etc.  At some point the engine speed will drop off just a bit.  Technically the max speed is perfect, not to rich or too lean.  Of course having a gas tester you can just adjust this to get about 5% at the tail pipe.

I usually set a couple notches rich for two reasons: 1) lean engines can run hot and get damaged, rich engines don't and 2) the stock fuel injection mapping is a little lean in the low revs to meet EPA/ECU emissions, the reason there are so many lean popping problems with these non-O2 sensor bikes.  You can get a PC3 and all that or just add a little fuel.  You'll run a bit more rich than you need at some of the low revs but just enough around the 3-4k range.  This is how I set my bike up.  I get a little less mileage but crisp throttle response with no pops or backfiring, all with a completely stock ECU.  My plugs are a nice light tan like they should be.

Ok, now an overview of the whole procedure and some details on how to use your gas analyzer and tune the cylinders individually.

1) Get the engine up to full normal operating temp.  Have a fan blowing on your engine so it doesn't overheat.
2) TPS reset (see above).
3) Kill the engine.  You need to gently seat both air bypass screws and then turn them out exactly two turns each.  If you've never done this there may be plugs over the screws, remove them.
4) Start the bike.  It may take a little throttle to run, the air bypass screws control the idle speed.
5) Open both air bypass screws the same amount to get as close to proper idle as you can.  Idle speed is usually on a sticker under the seat, around 1200.
6) Synch the throttle bodies.
7) Set the Fuel Trim (see above).  You can set it either by the idle speed method above or use your gas tester.  Just stick it in one tailpipe for now and shoot for about 4-5% CO, we'll fine tune later.
8 ) Now keep repeating steps 5, 6, & 7 in that order.  Make sure to adjust both of the air bypass screws the same amount in or out every time, you want them the same number of turns out.  Each of the three settings (idle speed, TB synch, fuel trim) affects the others to a small degree.  By iterating several times we hone in on getting it just right.  You'll see, it will be a little rough and then get smoother every iteration.  After a few iterations you'll be done.

Now that's usually it, but you can tune each cylinder's air/fuel mixture individually with a gas tester.  You can't really do this at the mufflers, you will need to be able to hook up your gas tester to the exhaust bungs.  These are the little allen head screws on the exhaust header.  If you measure here you can get an accurate reading of the cylinders individually.  Also measuring here, you want to shoot for 6-7% CO.  As the gases travel down the pipe they are still hot enough to react and some of that CO combines with available oxygen and becomes CO2.  You lose about 1-2% CO along the way.

Getting back to individual adjustment, measure each cylinder.  If they are different you can lean out one or richen the other to get them even.  You do this with the air bleed screws, now they won't be in the same position   If you turn it in, less air, richer mixture.  Turn it out, more air, leaner mixture.  Adjust one or both a little.  Don't worry about absolute value, just get them the same.  Now that they are the same use the Fuel Trim to set the absolute level.  Now iterate again: TB synch, idle speed set, CO trim (individually this time).  You should be very close now and you're really just fine tuning, you shouldn't need many iterations.

Now, I think you're supposed to shoot for 4% at the tailpipe according to the official Ducati manual which will put you into EPA compliance.  The bike will probably run a little lean, may pop in the 3-4k range.  5% at the tailpipe (7% at the bung) and you'll run a little smoother and a little cooler.  That extra gas in the slightly rich mixture that doesn't burn acts as a refrigerant as it changes from liquid to gas and absorbs heat.

So when I first did this I used the Gunson spark plug that has a window in it to set the mixture.  It's really cool, little window and you can actually see the flame front in your cylinder.  White/light blue means too lean, red/orange means to rich, nice blue is just right.  Adjust as above but just check each cylinder by color instead of %.  I found that on my engine the cylinders were about the same so I didn't need to compensate between them.  Also, once I had done it a few times I could find the sweet spot just by listening to the idle speed and didn't need more than that.

A side note: if you have the Gunson Gas Tester I hear it is a good little unit but needs to be treated with some patience.  It reads accurately but not quickly.  Take your time.  I'm sure you can find some postings on the web from people who use it.

Oh, and if you don't have LT Snyders (Desmo Times) manual I suggest you get it.  Also read Brad Black's pages on fuel injection.  Kind of dense but makes sense of it all.

Scott

[Speeddog]

<bookmark>

[brad black]

i don't agree that the CO % changes depending on where you check it.  it is influenced by dilution tho.  the pipe i stick into the mufflers is about 1m long, and you need to push it a long way down.  std mufflers are almost impossible to get a good sample on - you need to put the probe inside a long tube to stop the reverse pulse of air getting to the end of the tube.  a 4gas is good for this as you can see the o2 rise when you have a bad sample.

there is only one mixture adjuster, but you use the air bleeds to even the mixture between cylinders.

the "idle speed" and "AFV" buttons are not used afaik.

[booger]

Wow Scott, thanks, I have the Gunson gastester and the LT Snyder book. Another question here, I've been using a butterknife with the tip bent to get to the throttle sync screw since it's so ridiculously difficult to access. There is a tool available that I thought was kind of neat from Holeshot Performance; a long thin right-angle gear drive screwdriver that's $85, but is there another cheaper trick or something to it?

[scott_araujo]

I removed the two bolts holding the oil cooler and just let it hang down by the front tire.  With it like that and the front wheel turned to one side it's pretty easy to get a long screwdriver to the screw.  Even easier if the tip of the screw is still painted with bright paint, you can spot it easily with a flashlight.  It's still a little awkward but I wouldn't spend $85.

This also lets you set everything with the air cleaner and tank in place.  I think the official manual requires you to have the tank off to the side and the top of the air cleaner and filter out.  That seems silly to me, it's a pain to set up the tank and the bike isn't going to be running with no air cleaner when you're done.

Scott

[booger]

Alright thank you Scott and Brad, that was the enlightenment I sought. I'm guessing to really get to the finer state of tune I'll need to go to the hardware store and get a fitting of some sort to fit the bungs and hook the gastester to those, which means I'll likely need a heat resistant hose as well. Now if I were to get ambitious and degree the cams, would that change the baseline on the fueling causing me to have to start all over with fueling adjustments? I'll have to add that I'm running a DP ECU. I'd simply like to exploit the potential of the engine as much as possible without going nuts and getting the PCIII and doing head work, etc, even though that may happen in the future. Most people would just upgrade but I happen to think the 800 wet clutch has a very tractable power band but I feel it's just not tuned very well out of the box.

I'd also like to add that I have done the air bleed screw procedure, and it seems that 1000rpm is all I could achieve by turning them out, as if it plateaus or something. I think they're both out by almost 4 turns, with no idle speed gains after that. What am I doing wrong here?

[scott_araujo]

I was going to suggest it but didn't want to get overly pushy.  Yes, degree the cams.  SOOOO worth it.  Once you do that you're going to want to go through this whole process again but if you do it before, you'll be pretty close to the right ballbark and just need fine tuning.  I had to degree my cams because one came loose and one cylinder wasn't firing.  Once I was done I was amazed how smooth it ran.  It seems almost everyone who checks them finds them 5 degrees off or so.  There's no way you're going to get peak engine performance like that, even with a PC3.  You can also get fancy if you want.  Advance the timing a little and you get less low end torque but more top end power.  I went with stock.

I'm with you, a properly tuned stock 800 is a nice engine.  And properly tuning it gets rid of most of the problems people are using PC3s to fix: lean pops and shifty throttle response in low and mid range.  Also, most people with PC3s aren't getting a custom map so really aren't getting all they can out of it.  My stock 800 fires up every time and always runs smooth.  If you're not going to do all this here why bother with the bolt on performance goodies?  Then again I think people should upgrade their suspension and work on their riding skills to get faster before they throw parts on their engine.  I'm not always popular

Brad, thanks for the info.  I didn't realize you snaked the collection tube that far up the exhaust.  I think that just putting it in near the tailpipe would also account for the Gunson tester being noted as finnicky, it's getting a diluted sample.  On a side note, one difference between my Dark and a later S2R is that the S2R has a catalytic converter in the udder.  This would definitely change your readings at the tail pipe.  I think Gunson sells a kit with several different screw in exhaust adapters to hook the thing to a bung.  With what Brad said and the catalytic converter, this is going to be your best bet for accurate readings.

As to why you can't get the idle higher with the air bleeds, I don't have an clear answer for that.  Are you running full stock air box and exhaust?  Maybe the fuel trim is set really lean and if you richen it up it will work out just fine.  It's certainly worth trying but I wouldn't bet the farm on it.

Scott

[booger]

I've got the DP airbox/ECU running a cat eliminator midpipe with fully cored stock freeflow mufflers(perf tube+muffler packing).

What would I need to buy to degree the cams, and where? The shop manual outlines the procedure, but it's best to have some first-hand experience to boot.   

[scott_araujo]

So your intake/exhaust set up is not stock but it's a mostly matched set.  I don't think that's your problem with the idle.  Check the fuel trim or ask Brad who knows way more than I do. 

When I got my bike it was set to idle at 800, god knows why.  It was sold new to my friend like that, I bought it from her.  It took forever to warm up.  I opened the air bleeds a little and that was better but then I had to wait a week or so to get my VDSTS to get it any higher as it was already way lean.  Since then it's been great, idles right around 1250 and super smooth.  Interestingly, I once tried to get it to idle down at 800 again and couldn't no matter what I did.  Who knows.

For the cams you will need: an engine turning tool, a degree wheel that mates to it, a dial guage to measure valve rise, and a clamp to hold it to the head.  You can buy all of this for not too much or...

I got the $20 cylindrical engine turnging tool, downloaded a degree wheel from the web, printed it on cardboard, and glued a little nut to the turning tool.  The cardboard wheel bolted right up.  Very cheap.  I bought an inexpensive dial gauge at harbor freight ($10) and bent a heavy gauge steel wire into the right shape to hold it in place when bolted to the cylinder head.  I put a small washer under the dial gauge head to ride on the valve as it moved.  Again, really cheap.

I'm sure it would have been a little easier to do the job with a degree wheel that didn't fold when I nudged it and a nice CNC machined custom mount for the gauge but I was only doing this job once so I went frugal.  It turned out fine.  As with many things, patience is more important than skill.  It took me a few days to figure it all out and then nudge it back and forth a few degrees a few times to get it where I wanted it.  In the end one was dead on and one was 1/2 a degree off.  Good enough for me.

While you're at it, the only other thing that might need to be done is adjusting the valves.  Make sure you do that too.  No sense skipping that if you're doing the rest of this.

Scott

[brad black]

if it's lean winding the air bleeds out to raise the idle speed also makes it leaner, so it might be too lean for the speed to come up.  try winding them in and see what happens.  or just trim it up and see if the speed climbs.

[scott_araujo]

Did I mention you really should read Brad's pages on fuel injection?

[booger]

I'm grateful guys, thanks for the info. I adjusted the valves about 1500 miles ago @7500- I'm now @ ~9000 and the bike runs okay, seems to be a flat spot in the low to midrange. So I suppose I'll go out and get a dial gauge. Got the turning tool, made myself a degree wheel, that's it? I don't need a castle nut tool or a cam wheel holder?