Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > 998(9) engine wont start

[smilo006]

is there a definitive list somewhere of what to check if your bike wont start?

So far:
Battery - fine, given extra juice of seperate battery as well
fuel pump - changed tank and still wont start, fule pump sounds like it is doing its thing.
Fuses - fine
Side stand cut out annoying plug thingy - fine
On off switch - on
Spark plug ht leads - fine
Power commander - lighing up as it should
Starter - cranking away as it should
ECU - seems fine. With throttle open, bike tries harder to start etc.
Fuel line, changed last year - therefore new(ish)
Could the fuel filter get blocked?
Both coils done in
Relays? if so how to check and which one
???

shazaams update included:
Engines need more fuel for a cold start because there is no heat in the ports and chambers to keep the fuel atomized as vapor, so it stays as a liquid. Fuel as a liquid burns very badly in the combustion chamber, so throwing extra fuel at it ensures enough stays as vapor for some sort of combustion. Too much fuel and you foul the plugs.

One of the problems with shower-type injected bikes like the 999 is HOW you start bike can result in problems. You can easily flood or foul plugs with shower injectors because much more of the initial fuel spray from shower injectors condenses on the cold surfaces of the throttle bodies and intake tracts before it can get down into the combustion chamber to aid startup.

So the method of starting is different.

In particular, do not open the throttle or engage the fast idle lever until the engine fires up. You must simply hit the starter button and wait for the engine to come to life. Attempting to crack the throttle open will only force you to run the starter motor longer (and possibly drain the battery). Once the engine begins to idle, you can open the throttle or fast idle lever at any time.

[skidlids]

Replied in the other post
But the things that control both the fuel and ignition maps are the revs and the throttle opening, these are then trimmed by the various sensors to get the mixture correct.

As such a problem with either the TPS or the crank sensor is fatal for the bike as these are the main inputs to the ECU, there are a several other inputs, as mentioned there are other sensors such as Air and water temp, then there are a couple of Interlock inputs, most of which prevent the bike cranking over when in gear, such as neutral & sidestand

Outputs from the ECU are mainly the Ignitin pulse to the coils and the injection pulse to the injectors, via the power commander in your case which also taps into the TPS signal. This it usually does with a very poor connector that can if not careful braeak the TPS wire preventing the signal getting to the ECU

Not sure which ECU a you are running
Has the bike been running OK previous to this isssue

[smilo006]

Another item to check. The power commander seems to be lighting up as it should when the throttle is turned. However will check the wiring on that.
My 996r was never especially good at starting and this not much better. However before I took it to Alta Mura to ge the wheels done and the fairing painted it worked fine. Has been at Cadwell and Brands last year and was great. Has not been used for a while - never a good idea with these.
If I took it to Italy on holiday it would likely start immediately of course!!!