S4 cutting out

[doc916it]

Last October i bought a S4 ( 2001 model ) which had been stood in a shop for about 9 months, after buying it i took it to my local Ducati dealer to check the cam belts , which were fine but they said that it needed to be set up on their dio machine, but it would be fine to ride till the spring . Rode thru the winter here in France and it seemed ok but for having to turn the ignition key twice to prime the pump. but now in spring and summer it has developed into a misfire thru the injection (a sound like a PHUT ) and some times it cuts out , also on changing down the gears with a blip of the throttle the same can happen. It has been in the  dealers to be set up and they say that the settings are all ok but feel that it must have an intermitent electrical fault which they are struggling to find .
Anybody out there who has had a similar problem , HELP 
Doc>

[johnster]

Yep, same problem here!!  Here's a thread from a  while ago that I posted:

Basically it's some sort of ECU issue (we think) that causes a backfire up through the airbox. Mine only does it around 3000-4000 RPM's with the throttle cracked open and not all the time, so I just sorta live with it.

http://ducatimonsterforum.org/index.php?topic=802.0

[clubhousemotorsports]

lean condition, probably TPS. have the bike richened up a bit and it should help, no need for power comander just get it to someone that understands fuel injection systems and has the tools to tune them.

[doc916it]

lean condition, probably TPS. have the bike richened up a bit and it should help, no need for power comander just get it to someone that understands fuel injection systems and has the tools to tune them.

Thanks for reply, i think that you are probably right ,the Ducati shop thought it might be an eletrical fault and so i checked all the wiring an found 2 wirers were almost cut thru at the headstock, this i have repaired but still the same problem! So checked the plugs and found them to be running very hot ( white electrode) so rang shop and they said they would reset it up more rich,i have just had it set up for the emissions and they thought it was to rich so leaneb off, but in fairness it was doing the same thing before , will keep you posted on the result.

[clubhousemotorsports]

It is more than just richening up the map, they need to make sure the bike is richer in the map where the problem is.

[jerryz]

The S4 is very very sensitive to its TPS setting it must be spot on 150mv for best low speed running .

[hydra]

bonjour et bienvenue!!!

good luck with your S4...these guys here will get you going in the right direction!

[doc916it]

Bonjour et beinvenue a tous
Thanks for all your help in this problem, have taken the bike to ducati shop today and have had it on all their machines, we have reset the TPS and checked many other things ( ie : wiring and air leaks) and all is ok, but  now  and again it still does a little hickup but does not cut out ! How ever we did find that some times the ECU cut the fuel pump and switched the fan on for a fraction of a second which might be a break  down in the ECU unit, the mechanic said it is proberly cheaper to get a exhaust with a ECU than buy a orignal one but we will see !!!
Thanks again for all your help and i like to read the web site and see all the other problems you guys have with your Ducs! Its a good thing we love them i think !!!
And now i am going for a
Salut mes amis ( Goodbye my friends )

[jerryz]

S4 really benefits from a PC3  but still hiccups a bit at tickover.

[doc916it]

S4 really benefits from a PC3  but still hiccups a bit at tickover.

Thanks for that jerryz,
I know that this is gonna sound stupid, but I am new to all this technology stuff, mapping , PC3, TPS etc etc, when I started biking it was a minor adjustment with a screwdriver and an empty cigarette packet, but seriously what is a PC3 , also I cannot find a workshop manuel for a MS4, I do not know if one is in print yet,
Cheers
Garry

[Speeddog]

A PCIII is an electronic device that monitors the TPS (throttle position sensor) and the fuel injectors, and intercepts the signal to the injectors and modifies it, then transmits it to the injectors.

It can be loaded with a 'map' that will alter the fuel mixture based on rpm and throttle.

Don't get the EX model.

More info here: http://www.powercommander.com/eng_default.aspx

Workshop manual can be bought from a dealer or downloaded from the internet, I don't have a link for that.