Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Sport Touring: ST4 / ST3 / ST2 > ST4s idle settings

[nelly]

Originally Posted by ducatiparts.110mb

I thought setting the TPS with the throttles completely shut was the way to go, then use the throttle stop to hold the butterflys open the correct amount for the idle speed once the trimmer and air bleeds are set.

Yep. That's the way. The idle values are fairly ambiguous tbh, as more air bleed and fuel trim would need less throttle stop and hence a lower mV output. Useful for checking but the closed set with 150mV is the way to go.

[ducatiparts.110mb]

UPDATE - Yesterday I reset the TPS using the tenhoresearch software (I'm not sure whether this has made a difference as the ST4s has a manually adjustable TPS, but I was advised to do it on other forums. I've also made the mixture 5 points richer and now the bike pulls much better with an improved throttle response.

The idle is still a bit rough - a touch too fast yet occasionally stalling, but once the throttle is open its much improved. I'll tinker with the idle over the next few days and post an update, but for now its what I wanted (at least once you're moving).

Thanks to everyone who posted advice. Cheers, Mark

[jerryz]

The TPS is a very difficult thing to get exactly spot on it often moves when the screws are retightened .Check and check again.

[nelly]

The ST4 uses the non linear TPS. You can't reset it in software. That function is for the linear TPS used on 749/999 etc. It's a function that shows up in VDST because of the 5.9 ECU being used.
The extra click on the mixture have probably given you the improved running. The TPS reset could/will have thrown it out.
Only way to set it is with closed butterflys and the 150mV setting.

[jerryz]

I have been thru all this with my S4 and have cured all poor running problem by using a PC3 with termis and airbox mods then setting up and writing a series of custom maps , I now have a perfect tickover with easy running at low revs and great transitions to mid and onto the rev limiter , there are no glitches at all and around town the bike runs smooth as silk at 30mph in 4th gear .
I find that the TPS is most critical of all service jobs even if valves and balance are perfectly set the TPS is more critical for perfect smooth running .I check it now at 2 monthly intervals as it goes off very subtlely .