S4rs hesitation, power loss & stalling

[roggie]

Bike: 2007 s4rs w/slip on termi kit, approx 2400 miles

I think I may be experiencing the throttle body / TPS issue that some s4rs owners experienced back when the bike originally was sold.
Twice on the expressway with speeds in the 80s I have revved the engine from around 5k to 7-7500k and have lost power for a second. The power would kick back in with an unsettling jerk and run fine after that.
This weekend however I was riding for an extended stretch around 44-50 mph, roughly 5500 rpm, again accelerated hard to 7500 rpm and the bike lost power, the engine light came on and I had to pull over. As I was costing to a stop I revved the throttle and power came back and the light went away. I then pulled over a short while later turned the bike off for a few minutes and then started it up again. The engine idled very rough and stalled 3-4 times when I proceeded to roll off. I stopped at my destination shortly after that and the bike sat for about 30 mins. When I fired up the bike again it ran fine and I had no issues the rest of my ride. I didn't really rev the engine much past 6500 though.
Does this sound like the TPS issue? I checked with the dealer and there have never been any service bulletin or recalls performed other than the tank issue.
Does anyone have the exact info on the TPS sensor that I can have my dealer reference? I plan to pull the sensor when I get home tonight to see if it seems corroded.
Or does this sound like another issue all together ?
Any help would be appreciated.
Oh and I just bought the bike last summer with only 130 miles on it.

[JimmyTheDriver]

Yes, it does.  That is EXACTLY what mine felt like before I got it fixed.

I bought a 2007 S4R in 2010 w/ 7 miles on it.  It ran like shit but I was none the wiser.  I posted in a here a few times and was convinced it was "ducati charm".  Thank god a reputable Ducati shop knew about the issues.

When I was stumped, and the local shop was stumped, I decided I would just get it dynoed elsewhere.  Maybe it would show the power loss, a messed up AF ratio, whatever.  I brought it to Duc Pond Motorsports in Winchester VA.  Donnie, the owner, happened to be the mechanic who took the bike back for the dyno run.  When I met him inside, he said "does it always run like this?"  It did, and long story short, he did't dyno it and I ended up with the bike in the shop for a month while they got the parts and fixed it all under warranty.  I don't recall the actual fix if it was entire ECU, just TPS, etc, etc.

The bike I got back from felt like a completely different motorcycle.

You need to go somewhere where they will attach a computer and analyze.  Duc Ponds could immediately see the issue when at full throttle on the handlebars, the bike was doing anything from 20-80% throttle down low.

Where are you located?  

-Jim

[roggie]

Thanks for the quick response Jim. I'm in Michigan and my dealer so far has been pretty good with issues I've had in the past. I am actually waiting for a call back from one of their techs.

Maybe I should mention that the bike seems to run fine 98% of the time. I had the belts changed about a month ago and before and after the bike seemed ok. Nothing like I experienced this weekend.

I found in another thread which sensor to check but are there any other things I can visually check that would confirm this issue?

Thanks again

[JimmyTheDriver]

They initially noticed the problem by attaching a computer, twisting the throttle, and checking the basics, like throttle position.  They noticed major inconsistencies right off the bat.  Sometimes it was almost a match, say 100% open via bars, and 80% registered on CPU.  Other times, it was full on bars and like 20% CPU.  I am in over my head discussing it much further, but to my understanding, that causes major issues.  Air/fuel ratio is thrown off big time when you basically have two components thinking they are at completely different throttle positions.

I called Duc Ponds just now and asked what they did, but the record they could find is kind of skimpy.  I have it down on paper somewhere but likely in storage.  The lady said she shows "full cpu replacement under warranty".  I vaguely remember the TPS and ECU were replaced.  Also recall them talking about replacing the entire throttle body, but I don't believe it came to that.

Don't hold me to all this.  I just know my symptoms were very similar.  

He did show me one way to do a basic test, which my bike failed (hence the repair).  Hold the throttle somewhere, say, 3-4k RPMS while in neutral.  My bike coulden't hold a consistent RPM for more than like 10 seconds.  You could literally see/feel the TPS reporting different positions, which in turn fluxuated the RPMs.  My bike did it worst at a specific RPM, I feel like it might have been between 3.5-4k, but again, this was years ago.

-Jim

[roggie]

Thanks a lot Jim this is great info. I appreciate you calling your dealer too!
Ill check the sensor and try holding the throttle later this evening and report back.

In the meantime if anyone has more specific info on the recall/ service bulletin (if there even was one ) please let me know.

Thanks
Matt

[roggie]

just tried to hold the throttle open at 3000 RPM while in neutral and it didnt fluctuate more than 250 rpm up and down. Is that normal?

i was going to pull the sensor and see if there was any corrosion, but if the sensor that i am supposed to check is this:

http://www.ducatimonster.org/forums/attachment.php?attachmentid=51060&d=1210099112

i didnt want to take off my charcoal canister and horn to get to it.
I will be calling the dealer back tomorrow, for anymore insight, but most likely they will need to see it in person. I just hope this turns out to be a recall or TSB issue so im not stuck paying for the parts for what seems to be an old known issue.

[abby normal]

when i had an ECU reflash on my 2004 S4R, it started to run like that (never did before).
the tech found that the ECU had a bad value in the TPS register.  they claim that the
stored value was somehow corrupted.  2nd time was the charm, and no problems
for a few months now.

[Bill in OKC]

I had read someone found that rain/water would travel down the cable somehow and come to rest in the TB connector and corrode it.  I have taken my connector apart a few times and cleaned/sprayed inside with Kroil and dried it off.  The official factory fix was a complete replacement of the throttle bodies as they had redesigned it so the TPS could not be removed.  I have however seen a replacement TPS on ebay from Eastern Europe....  maybe it is possible to carve out the epoxy/potting and remove/replace the TPS somehow?  The first time I saw it I was curious, the second time the price had nearly doubled to around $100 and that is too much to experiment with I think.  The Technoresearch tool I have - and others I'm sure - allow a real time readout of what the computer thinks the TPS value is.

edit:  Here is one from the UK wow that is a lot of money - maybe they just pry out?

http://www.ebay.com/itm/Ducati-Superbike-TPS-sensor-Magneti-Marelli-IPF2CB-/290636761358?pt=UK_Motorcycle_Parts_13&hash=item43ab4d090e&vxp=mtr

[Speeddog]

Here's a replacement TPS from one of our sponsors, California Cycleworks:

http://ca-cycleworks.com/products/electrical/ipf2c-b

[Bill in OKC]

That price is much more like it!  I *thought* I could see some kind of glue around the edge of mine, but in searching around I've read that it is easy to replace these 'non-replaceable' TPS's but no instructions.  Would you just grab the old one with a pair of pliers and rock it out?  Then even though they get set in software there must be a way to orient the new one.  Would just pointing it the same way be accurate enough?  Hope this is not a thread jack.

[roggie]

Don't worry about the thread jack if someone can confirm about replacing the sensor and its position please post it up.

Talked to the dealer and my VIN didn't fall under the TPS service bulletin (or any for that matter).  Taking the bike in this weekend. Hopefully it's nothing major.

[Bill in OKC]

FWIW I bought one of these sensors from California Cycleworks and have a spare set of TBs that may or may not need a new TPS.  I'll find out how hard it is to replace this thing the fun way!

[roggie]

FWIW I bought one of these sensors from California Cycleworks and have a spare set of TBs that may or may not need a new TPS.  I'll find out how hard it is to replace this thing the fun way!

Cool, please let us know! Pics would be great too because I think that link I posted was a different component. Wouldn't the sensor be attached right on the throttle body assembly?

I was also thinking about the technoResearch tool too.  Found out they are based around the corner from me. It looks like it can do quite a bit more than just read codes. (which most of you probably knew that)

I'm going to wait now to take it to the dealer. Rode the bike again today and it seemed fine???
I don't want them to start throwing parts at it since its way out of warranty and my VIN isn't under any of the service bulletins.