2007 Monster S4r fuel or ignition issues

[marqueson]

Hello all, I am having some serious issues with my Monster, and I am hoping someone here can help somewhat before I have to cart it to the dealer and turn over my first born! It's an 2007 S4r Testaretta, with 5200 miles, a FatDuc 02 manipulator installed and the evap canister removed.  Other than that, it's totally stock. I bought it new in 08.
Let me say first that before it started running poorly, the yellow engine light came on for a mile or so, then it went out and started running poorly. And, that this has happened before - last year. But it disappeared after I drained the fuel from the throttle bodies and ran some dry gas thru it. At this point, I think that was a coincidence.
No joy this time! It is running very rough under load. Unloaded it revs up fine but sputters a bit when returning to idle. It will idle, but it doesn't sound normal(weak and lopey). No throttle response under load, chugs and bogs down when loaded. No backfiring, though. I have checked the coils and injector relays, and they all check out. I have replaced the fuel. I have run dry gas thru the fuel, fuel injector cleaner, etc. Nothing seems to help.  Plugs look nice and tan, oddly enough. It almost seems as though it's running on one cylinder?  But, the plugs would show that.  Also, I noticed that both times it has run this way, the temperature display will not go above 166F while running - not normal.
Has anyone had a similar problem that they can share or perhaps guide me to the correct fork in this road?  I don't want to start replacing things until I know what the issue truly is. I have the shop manual, but it only gives diagnostic info on the injector relays and plug coils.  Does anyone out here have diagnostic specs or procedures for any of the other sensors, etc. on this bike?
Thanks for your time.  Marq

[Howie]

Since the check engine light came on there is probably a trouble code in memory, so the best place to start is to use a factory scan tool or VDST software to retrieve codes and work from there.

[marqueson]

Thanks for answering, Howie. Much appreciated.
Looked into the VDST software and it does seem like the best way to start.  One question: Will the VDST software work if the ECU is corrupt? I dont know that it is, just trying to think ahead.
Marq

[Speeddog]

AFAIK, the VDST software won't work if the ECU is corrupt, but I'm very confident that your bike wouldn't run at all if that was the case.

Just to eliminate one potential issue....

Pop the fuel filler open, and turn the key on.
If the fuel that's in there shows some churning, or there's fuel spraying around, you've got an issue with one of the fuel lines in the tank.

[marqueson]

Thanks, Speeddog.  I'll check that tank fuel line issue out.
On a related topic - I have ordered the VDST software, so I'm confident that I can diagnose whatever issues the bike may have. However, since it is still under warranty for another month, ultimately it will require a trip to the dealer to fix. Question: should I remount the evap canister before I take it to the dealer.  Does removal void the warranty?
Marq

[Howie]

Removing the canister would only be a warranty problem if it was related to the problem you are having, rather unlikely.  I would be more concerned about the Fat Duc.  If you disconnect the Fat Duc and run off the normal O₂ sensor.  If the bike now runs fine the problem is the installation of the Fat Duc or the Fat Duc itself.

[Speeddog]

+1, pull the FatDuc out of the loop and see how it works.
It's a really cheap and easy experiment...

[marqueson]

I wondered about the FatDuc last year when this happened the first time.  I'll pulled it then and it did not seem to make a difference, but I'll definitely give it another try.  Question: Does anyone know if the VDST software will allow me to adjust the A/F ratio so I can do without the FatDuc?  Is that the 'fuel trim' setting they speak off?
Much appreciated, Gentlemen.
Marq

[Bill in OKC]

The VDST software will let you *think* you've adjusted the fuel trim.  There must be some leftover code in the ecu that sets a memory location.  The ecu doesn't actually use the value so it really does not do anything - unless you get the DP ecu or a reflash to DP specs - then you can trim it.  I wonder if a bad o2 sensor would cause the problems you are having.  Have you tried running it with the 02 sensor disconnected completely?  There is a default mode in the software and that would be a good test.  Finally, the VDST will let you set the TPS so set that too.  Some of the 07 s4rs TPS's had issues with water getting in the connector and corroding.  If you can, try to disconnect the TPS connector and inspect the pins, maybe give them a shot of wd40 and clean them up if they look green.  Mine did and I wasn't even having any problems.  The VDST will also let you look at the action of the TPS.  Good luck.

[marqueson]

Thanks, Bill in OKC.  I have a sneaking suspicion that this problem is directly related to the throttle position sensor.  Just from the way the bike reacts when running. The RPM wanders all over the place, even if you're holding it steady.
Question: If the O2 sensor is bad, wouldn't the voltage output be outside of the normal parameters and thus operating under the default settings already? Just curious.
Also, I ordered the Technoresearch VDST. Are there any quirks, warnings, or Blue Screen of Death type situations that I should be aware of before I start tinkering?  Or, is it somewhat idiot proof?

Thanks again, Marq

[Bill in OKC]

A lot of those sensors have default values if the ecu can't get a good reading.  I ran my bike for several months without the o2 until I got the DP ecu - which doesn't use one.  The VDST is pretty straightforward, my biggest 'new user' issue was that you have to have the engine running before it will start communicating and I was trying to get it talking with the ignition on but the engine not running.  Anyway it has paid for itself several times over.

edit: I should add that technical support from technoresearch is first class and if you have any issues at all - they will support you.

edit #2: When these bikes were new, a few throttle body assemblies were replaced under warranty - the TPS is integrated into them.  IF it turns out to be a TPS issue and cleaning the connector doesn't clean up the signal, I wonder if Ducati might still replace it under warranty...  Try searching, but I think there was a path for water to travel down the cable and end up at the connector.