My 999s 2005 has given various troubles since new including poor running and most recently refusal to prime or start, sometimes. One day fuel pump primes and it starts, next or a week later and it refuses. Stalling at end of braking for roundabouts etc.. Eventually I get it to that genius Eddie Stone at Knockhill, turns out to be bad connection inside fuel tank same as his 999 racer of same year. For years at services I had asked the dealer to check out the problems, one time I was lucky to get it started outside the shop after a service and it stalled several times on the way home. not to mention the missing bolts and bad radiator connection.THank you Eddie
This is not for the st2, the ST2 has only 2 wires coming out of the Stator to the Regulator,this is quite sppecific to that single model. Later models got a 3 phase satator with 3 cables... at least that is what I have been reading about. I have asimilar problem, but in my case, both the pump doesn't prime and the plugs have no spark... Change the ignition relay, same issue, swap them, try new relays, same... curiousy, as I was removing the relay, suddenly the pump started to prime, and pushing the start button, the bike started. That was like a dream, but short one, I was unable to reproduce that anytime after. I have checked all connectors, cleaned them and fix others (not related to that circuit though). Last step is to check continuity iin the harness loom and see what is going on and where, I have an extra back harness loom on the way from the UK now and an appointment at a Ducati workshop next week... so hopefully I will find the faulty wire in the next 7 days!
Most likely this caused by one or more of terminals in the relay base being a loose fit on the relay pins. Disturbing the relay created a temporary connection that obviously didn't last. You can remove the terminals from the relay base by pushing back the locking tang and pulling them out to the back of the base. Test each one on a relay pin and if necessary give it a slight squeeze with pliers to make sure it grips the pins securely then push it back into the relay base. Take care not to mix up their position.
Ooooh... I will try that... Actually I tested a bit the relay half way inserted with the multimeter: (The relay is new and clicks when I turn on the key.) Continuity on pins 85 & 86: positive From the pin 30 to ground I get about 12V reading (same voltage than the battery actually)... But testing from pin 87 to ground (after the relay has clicked first time), nothing... I also tested continuity from the pin 87 to the pin 1 of the fuel pump connector (following the wiring diagram of the st2) it was correct and that same wire goes to the coils (no spark) If i understood the principle, the pin 87 to ground should give me the same reading as pin 30 to ground when the is internal contact between them, right? (I tested the fuel pump connecting it to the battery directly and it works) Could it be any other reason that the current doesn't reach that cable from the pin 87 of the relay? Like a fault detected by the ECU and cutting the power to that connection? I was thinking Crank Position Sensor, but when it was working, the pump primed before the starter makes the engine turns and the CPS sends signals to the ECU... so... confused, confused...
