Bad Throttle response - Ducati.ms

Desmo_Duc · Mar 26th, 2006, 6:18 am

Another question for you all...I love my 04 ST3, but the throttle response is terrible comaperd to my last bike (Suzuki TL1000R). If I'm in a neighborhhod or the city (which I hate driving in anyway), if I'm at low speeds, and I let off the throttle (get's down to like 3k rpms), then twist the throttle a little to speed up gently, nothing happens, it sounds like it's hissing/backfiring up through the fuel injectors, then the the bike lurches forward. I'm a little concerned since I'll be putting on some Leo Vince exhaust in a week or so, and don't want to make this situation worse. My dealership ordered me a new ECU since he said that he thought mine was 4 or 5 letters old. He said they were up to like L. Anyone have any experience with this and do you think the new ECU will help? I had the exhaust springs recall done at the end of last year which made the bike 90% better than it was...Any help would be appreciated..

Thanks,
Chris

mwkingsandiego · Mar 26th, 2006, 10:14 am

I have an '04 ST3 also - mine was pretty rough at first when going a steady speed between 2000 and 3000 RPM, but nowhere near as bad as yours sounds. At the 600 mile service the dealer tweaked the injection, and made it better, but I avoid steady speed in that RPM range. Was something of a challenge for me coming from 11 years on Gold Wings where there was no reason to ever exceed 3000, but I've adjusted!

Sounds like there is something seriously wrong with yours - press the dealer.

sperho · Mar 26th, 2006, 10:39 am

If a new ECU doesn't immediately solve the problem (test ride it carefully before you leave), be assertive in requesting that they also check the throttle position sensor voltage, throttle body balance, and CO output. Those three things must be set well for these engines to have good running characteristics, especially in the sub-4,000 RPM range. If they tell you that popping, coughing, and BIG lurching is normal (a "little" jerkiness is to be expected in parking lots), find another shop or do the tuning work yourself. I did the latter and have been quite pleased with my '04 ST3's smoothness ever since.

Bill_Anderson · Mar 26th, 2006, 1:16 pm

I recall there were some recalls associated with the first ST3's: ECU's and valve springs if memory serves me correctly. Could this be part of your problem? Search the archives for more details.

sperho · Mar 26th, 2006, 2:02 pm

Quote:

Originally Posted by Bill_Anderson

I recall there were some recalls associated with the first ST3's: ECU's and valve springs if memory serves me correctly. Could this be part of your problem? Search the archives for more details.

Bill: He mentioned in his first post that the exhaust springs specified in the Service Bulletin were done...

Desmo_Duc: My experience is that the exhaust springs solve the major problem. I have the stock ECU, but the new springs and I've been able to attain a pretty good tune for lower RPMs.

Desmo_Duc · Mar 26th, 2006, 4:32 pm

Thanks all! I'm going to tell them about it when they put in the new ECU...The dealer is really good to me...They ordered the ECU because they new there had been a bunch of updates since mine was last done. That way when they put the aftermarket exhaust on, they can tweak it all...Thanks again and I'll let you know how it comes out. I still love this bike, WAY different from my TL1000R, still getting used to the look of the panniers, but man are they useful!!

YveST3 · Mar 26th, 2006, 4:41 pm

Quote:

Originally Posted by Desmo_Duc

if I'm at low speeds, and I let off the throttle (get's down to like 3k rpms), then twist the throttle a little to speed up gently, nothing happens, it sounds like it's hissing/backfiring up through the fuel injectors, then the the bike lurches forward.
My dealership ordered me a new ECU since he said that he thought mine was 4 or 5 letters old. He said they were up to like L.
Anyone have any experience with this and do you think the new ECU will help? I had the exhaust springs recall done at the end of last year which made the bike 90% better than it was...Any help would be appreciated..

Thanks,
Chris

I've has the same symptoms when they changed my exhaust springs without changing the ECU.
When the dealership changed the ECU, 3000 miles later, all was fine at last.

YveST3

7234 · Mar 26th, 2006, 7:39 pm

Desmo Duc, Ditto what the others mentioned; my 04 ST3 got the ECU and return springs changed out under warranty at my 12k service I think it was, noticeable change for the positive. After the Leo Vince's are on I'd be interested to hear your take on them; describle the sound if you will.

Thanks in advance, jim

Willy_Mac · Mar 27th, 2006, 2:55 am

The stalling / surging problems associated with my wife's 04 ST3 were all resolved with the closing springs and ECU that were replaced under warranty. When we installed DP CF silencers and air filter on her bike, the DP ECU that was supplied with the silencer kit unfortunately caused some spluttering and stalling at low revs. This ECU was however also replaced under warranty and everything is fine now - the bike is running great.

Desmo_Duc · Mar 27th, 2006, 5:41 am

I don't recall them saying they replaced the ECU when they did the springs, but maybe I just forgot...I'll keep you posted and jbourque, I'll let you know how the CF Leo's sound...I want a nice rumble, nothing too loud since they are very touchy around here about loud exhaust (couldn't get an inspection sticker on my TLR with D&D's)