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Hi, Just bought my first Ducati, 2005 ST3 , 12000 miles, Was a Honda tech for 11 years so have ridden a lot different bikes,but never a Ducati. My ST3 had just had the 12000 mile service done , (new belts and everything else recommended) before I bought it, I relocated it from sea level to 4500 ft where I live. My question is ,
is it normal for the bike to take a long time to warm up, temp has been around 35 in the morning, I let it warm up until temp is showing 120 on the panel before I leave. Riding town streets ( not over 40 mph) the engine is real rough running for about 4 miles or so, the temp never gets above 160 on the way to work,if I stop at an light once in a while it will spit and Dye when I start to go. Completely different when I ride in the afternoon when its hot, then the temp will get to 200-225 and usually doesn't go below 175 and the bike seems to perform perfect, Is this common or do you think should I take it in to my local dealer here and have it gone thru, Having never worked on a Ducati I don't want to take any chances. any feedback would be greatly appreciated, thanks,Mark in Reno
 

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Mine runs very cool as well, as far as spitting/stalling, the fuel trim can be set with an EGA/VDST or the new freeware deal is out as well.

The dealer can set the CO%/Trimmer and idle/driveabilty should improve, but they do run cool.
 

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My bike's a 4s, so maybe not apples to apples, but I normally see temperatures similar to what you've reported. But, my bike runs smoothly regardless of temperature, even when cold and just started. I usually only let mine warm up long enough to put my gloves and helmet on and then take it easy until the Low Temp warning goes off.
 

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Completely different when I ride in the afternoon when its hot, then the temp will get to 200-225 and usually doesn't go below 175 and the bike seems to perform perfect
Seems kind of high. My 4s never sees above 190, when moving, on the hottest days. When the temps are in the 80s to 90s, spirited riding sees 180ish. Stopped at a light or in slow traffic, it can get in to the 220s, but then the fan kicks on and keeps things in check. Sure the coolant is full? Also, coolant temp sensors have been known to go bad on these bikes. Low speed running problems are normally related to an overly lean mix that can be fattened up with the fuel trimmer. Not sure if the 2005 ST3 is still an open loop, or had Ducati gone to a closed loop system by then? If closed loop, you’ll need a fatduc or a race ECU which bypasses the O2 sensors to solve that problem. However, if the temp sensor was bad, you really have no idea what it is telling the ECU unless you can connect a diagnostic tool.
 

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The 2005 ST3 is open loop. Engine should run smooth from idle to redline in all gears no matter what the temp. That's how mine runs, that is why I love owning an '05, the last year for open loop.
 

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Discussion Starter #6 (Edited)
Thanks , yes the 200-225 is when I am stopped and I do hear the fan kick on. Thank you for your feedback
 

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Discussion Starter #7 (Edited)
thank you , not sure what open loop is all about, does that mean that I am able to adjust the mixture?
 

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thank you , not sure what open loop is all about, does that mean that I am able to adjust the mixture?
Open loop means it's not closed loop. :) ie no oxygen/Lamda sensor. No doubt there's a better way to explain it and maybe somebody more adept can chime in, but basicaly it's about how the efi sensors are linked with feed back to the ecu, ie sensor information goes out, and doesn't loop back for efi adjustments based on oxygen in exhaust gases to adjust mixture. Open loop bikes usually run better out of the box because they aren't tuned to Euro III emissions standards like 2006/7 St's are, ie you can slip on a pair of exhaust cannisters and usually not have tuning issues.

Are you using the fast idle lever on cold starts? :)
 

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Probably the only cure for the stumbling at higher altitudes, when cold, is to get the race ECU mapping (flashed aftermarket ECU), open the airbox and add pipes.

You could try tinkering with the CO via the air-bleed screws (if they aren't glued shut or missing on those models) and making sure the TPS is set properly, to try and get it a little better. However, the closed loop ECUs are mapped to run lean and cause the issues you are describing (with less air pressure at altitude they will run richer than the ECU can compensate for, when cold).

Edit: I'm a dumbass...the OP has a '05 bike. This bike should respond well to tuning the CO and TPS for a better experience. However, what you set at altitude will not be ideal at sea-level and vice versa, set it for where most of your riding will take place.

Also, there might be other issues going on. A check of the coolant temp sensors (both front and back units) would be advisable. I forget which unit does what, but one supplies the dash readout and the other the ECU data to calculate the mixture.

Edit 2: Reviewing the exploded diagram, the ST3 only has one coolant sensor off the vertical cylinder on the left side. However, unlike the other models, the '05 ST3 has an external temperature sensor as well, attached to the left coil mount, where other bikes have this sensor embedded in the dash. Possibly check both.
 

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Also, the coolant temps sensors might not be telling the ECU the right info, esp when cold. This winter with the NAPA sensors, I didn't need to block off my radiator and the throttle response was much better in the cold.

Also, there's is no need to warm up the motor. It will just take much longer to come up to temp. I am at sea level, but I don't start the bike until I'm ready to fasten my helmet, put on my gloves, and immediately ride off. I get maybe one bit of hesitation pulling out from the first intersection.

Have a good one.
 

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Discussion Starter #11
Thank you guys , great feedback, much appreciated
 

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Don't know if this is true, but this is what it feels like to me:

My 2004 ST3 appears to run in enriched mode when warming up. It runs rougher in that mode than normal running temp mode. If I want to force it into normal temp mode, I try to get the temp over 160°F. Otherwise, it appears to change over to normal temp after running for 10 or so minutes. After getting it into normal temp mode, it can drop down to 150°F and it still runs smooth.

Flip
 

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Discussion Starter #13
That is exactly what mine does, I called the Ducati dealer here in Reno and talked to their head Ducati Tech , he said from his experience that they do what ours our doing, seems like as soon as you can feel the heat coming up from under the seat its starts running perfect, thanks for your post.
 

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One little nugget. A Duc dealer is not going to replace the Duc sensors (that give false readings) with a more accurate aftermarket product. Just a thought.

The ECU will start enriching again if the coolant temp drops, not to mention the ambient air temp and pressure inputs. The difference is that your oil is now hot. The STs don't sense oil temp.

Have a good one.
 

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Thank you guys , great feedback, much appreciated
Seeing as you are new, and if you haven't done it, make sure you check the torque on your engine mounting bolts, especially the rear one *asap.* :)
 

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I purchased my 2004 ST3 last summer, 5000 mi. and in great condition. As far as I can tell the only mods to the power train are Staintune exhausts. I ride in Austin, about 450 ft above sea level and we haven't seen 35 deg F for about 4 months, mostly 85-95 deg F.

But, it had similar ridability problems; it wouldn't run smoothly until it was warm (>145 F) and stalled at idle unless I used a little fuel enricher, and I needed the fuel enricher to start it from cold even in warm weather. Recently it got worse; hard starting, down on power, needing more fuel enricher, so I took it to the dealer.

They did the folllowing:
Re-balanced the throttle bodies
Reset the TPS
Set the idle speed
Replaced the plugs with Iridium plugs.
Adjusted the mixture with an exhaust gas analyser

Not that much really. Since then it's run perfectly, I don't use the fuel enricher at all (that will probably change next winter), it doesn't stall, and seems to have more power, or at least deliver it more smoothly.

Unfortunatly I don't know which of the repairs actually fixed it...

Best,
Kate
 

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They did the folllowing:
Re-balanced the throttle bodies
Reset the TPS
Set the idle speed
Adjusted the mixture with an exhaust gas analyser (Personal fav)
The above list should be done every maintenance interval and is the key to a smooth running bike, especially at low speeds.

Just a note though. On these bikes, the lever on the left bar isn't a fuel enrichener, it is just a fast idle lever. You can do the same thing with the throttle the lever does, if you want to sit there doing it. Only the ECU can enrichen the mix.
 

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Discussion Starter #18
thank you for all the input, most helpful,
 

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I'll chime in too. I have an '06 ST3 with a closed loop system (O2/lamda sensor). Even with a fresh tune I still will have drivability problems until the temps climb up to 140°F. Once at operating temps (for me that's in the 150's when at 40 or below, 165 to 175 at temps above 40°F) the bike is nice and smooth. I haven't changed out any temperature sensors yet. I just let the bike warm up while I put on my gear and do the safety inspection. My pre-ride ritual.
 

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All with cold drive-ability problems might consider testing out a theory of hotter coils, wires and Iridium plugs (gapped properly). It's a known issue that the plugs on Ducs are gapped wide and the coils aren't that hot.

Someone should give it a shot.

.02
 
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