Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Cough and splutter!!!

[dave996]

While riding along and sticking to a constant speed if I suddenly want to put the power one my 996 coughs splutters then eventually takes off, the bike has been on the dyno and has a very smooth power curve but it is running too rich (apparently). I was told it could have something to do with the pots!!!!! (I got lost at that point and started to sing to myself in my head).

Any ideas and is it expensive?

Cheers
Dave

[keefer]

is it a twin injector ?
could be that if fits in the mid range ?

[dave996]

Do you want the truth......it's a 1999 996!

I couldn't tell you, I'm not that familiar with the bike yet

[keefer]

well a couple of things then.
has it always done it ?
is it an adjustable chip ?

[dave996]

I've had the bike for almost a year and it has done it since then.

It has been serviced in the last 2 months (12k) and a new chip was installed (996 s) which is not adjustable.

[keefer]

if i were you then i would get an adjustable chip (ultimap) then have it put on the dyno then they will be able to sort it out.
you said you were told it was to rich but they cant do much about it as its not adjustable, should make it a bit more lively too

[dave996]

cheers mate.

oh how much for the chip?

[keefer]

£100 - £150
try Nelly or Neil at sigma

[dave996]

It's just cost me £70 for the 996 s one

[Shazaam!]

keefer got it first!

Dual Injectors/Single Injector Conversion

All 996's came with two injectors per cylinder. Before the 996 model, only the SP and SPS bikes had dual injectors. However, those earlier bikes use the larger P8 computer which is capable of firing the injectors sequentially, meaning the second injector sprays only at the higher engine speeds.

The 996, on the other hand, is controlled by the smaller 1.6M computer which is incapable of firing the injectors sequentially. So the engine does not run well with both injectors firing at the same time, especially at low rpms where spray durations get too short to get good spray patterns. The fuel dribbles out.

According to FIM, dual injectors are not needed unless you're making more than 120HP, and so have developed a single injector chip for the 996.

Read more about it here:
http://www.moto-one.com.au/performance/996eproms2.html

This is a quote from FIM's site:

"We have two UltiMaps for the 996 Biposto '99/2000 model. There have been many problems with these models spitting on low throttle or cruise at low speeds. We have finally made a chip which cures the problem (type UM222), but requires that one injector be disconnected from each cylinder. This is because the 996 has two injectors hard-wired in the harness and we can't switch one off like we can with the 996SPS or early 888 computers. The benefit is that the single injector spits more cleanly at low durations than two injectors do ( because they have only half the time each) and idle and low throttle repsonse is heaps better. We remapped a 996 with this mod and the difference is incredible. We do sell a twin injector verison of the same chip (type UM221), but in most cases the UM222 works better, and is worth the effort."

[Edited on 5-20-2005 by Shazaam!]