Just found this, anything is worth a look. TomTom Senior Narcissista Joined Jan 11, 2005 5,737 Posts #17 • Dec 21, 2017 (Edited) Theres a good chance one of the fuses near the ecu is gone, this will make it prime endlessly and you cannot start the bike either. They are embedded in little rubber tuts, a 5A and a 20A. Typically the 5:er is blown here. If its blown put a good one in and cross your fingers, its either ok by this or if it blows again the ecu is fried. Experienced this a handful times.
I agree .... But only as far as the tank wiring is concerned . Next thing I would look at is the long multi-pole connector on the ecu . Disconnect it ( with the battery disconnected ) , wash it down with switch cleaner , look for signs of corrosion . Then try it again ..... doesn't cost anything but time ....
@Miika the pump will run continuously without supplying fuel, if it is connected positive to negative and negative to positive - the pump will run at ignition on, but it will be running backwards
Ill switch the oem chip back and try with that its just funny that it has work many yers with the other chip.
The connector to the pump goes only one way so i doubt that but ill check the flow that it will go the right way.
Thanks for posting link Steve - you reminded me of similar solutions years ago. I hope O.P. reads this as it sounds highly likely to be the cause - i.e. a chip that just needs re-seating (no rhyme or reason for why it works sometimes, but it clearly does) or chip pins slightly damaged or (as said above) chip in the wrong way but this last one least likely I would have thought.
No, it was done at a ducati dealership and it worked over 7years so i dont think the problem is the chip
Nothing helped from your advices. Tried to clean the connectors, change the chip and everything else, fuel system is working properly. The neutral light doesn’t burn could that have something to do with the problem? And all the fuses are ok.
We need a expert... @nelly #No offence to the wonderful members on here as they know their onions as well.
Paul, the pump is run by the ecu whenever it senses the engine rotating but it has a mechanical overpressure bypass set around 5 bar which bypasses the outlet when the demand from the injectors is very low, that way it can keep cooling its motor whilst constantly running. The tank assembly has a 3 bar spring operated pressure relief on the injector feed which dumps excess pressure into the tank. The pump also has a non return valve which is why is does not loose lots of fuel when you disconnect the fuel pipes. Start up prime is programmed for around 4 seconds to establish the starting pressure, as soon as the crank moves the crank sensor tells the ecu to switch the pump on. A question for Miika, what has been done to the bike since it was last run - except taking the pump assembly out and changing the pipes, pump and filter
This might be a silly one but I say it anyway. Is the new relay switching the opposite way? So power to the relay switches pump off? Turn the key, after a few seconds pump comes on continuous. Try to start the bike and the pump goes off as the ECU powers the relay.
