on the fiats that use that ECU there is quite a heavy earth wire from the engine ECU that used to come loose and cause all sorts of weird symptoms. is there a servo start on that bike and is it controlled via the engine ECU? It might be worth looking at that earth wire if you haven't already.
If it was the ecu the fuel pump wouldn't prime. Does anyone have st4s performance map I can flash? Incase somethings been corrupted but I doubt it
not necessarily. coil drivers are an issue with this ecu. causes it to go down on one cylinder. but I suggested the ECU earth. they are also v,voltage sensitive. if it drops below a certain voltage, the fuel pump will prime, but not trigger the coil drivers.
Not correct. The red/white wire to the starter solenoid is ignition switched 12V. The red/black wire to the solenoid provides a ground energising the solenoid when the button is pressed. This ground is provided by the ECU as long as the conditions with regard to neutral, side stand and clutch switch are met.
ground cable seems fine and I grounded it to the frame jic no dice. although its a bit of a ballache bypassing the solenoid and trying to do anything else. hopefully the replacement one should be here soon
ok, a negative, grounding 12 volts then, that will teach me to rely on memory, certainly a simple test to do either way.
O.P. managed to test successfully? but I agree it's wrong to assume anything when explaining anything I guess, but we all assume a certain degree of understanding between readers on here, just to avoid getting too pedantic Derek!
Seems to function as expected, with the multimeter prongs hooked up to the two thin wires going to the starter solenoid its 0v, then when i hit the starter it goes to 12.x whats a servo start? the problem now is still no spark, but fuelling is fine and starter motor is fine. i also removed CPS today and cleaned it, the head was all cracked, so not sure if that means its on its way out.
I think Finm is talking about the starter button function type - when you push the starter button (normally) does the starter keep churning even when you release the push button?
it feels like some condition isnt being satisfied for spark. so far am told: 1. side stand up 2. bike in neutral 3. cps working 4. kill switch down what else is there?
can you obtain fault codes from this bike? this looks interesting:- file:///C:/Users/Dell/Downloads/ST4s%20ECU_Starting%20Issues.pdf
Yes I can, it throws a U1600 which is immoblizer...could that be it? even though the immo is disasbled?
With dodgy third party wiring and an indicated immobilizer fault, seems like you need to start in more obvious places. How is the immobilizer disabled? What has happened to the bike since you last had it running?
so the bikes been sat for a month or two. nothing has been done, its been sat under a cover and its rained. i dumped the ecu with guzzidiag reader and loaded it with tunerpro rt with the xdf file from the guzzi diag website and the immo box was already disabled around the summer I dynoed this bike, it made 120bhp at the rear wheel. so it seems its already been remapped and the lambda sensors have been removed.
