I was called out by a member of the forum yesterday, who shall remain nameless...
Coming down the A92 dual carriageway he lost throttle response in his 147 Sele, and shortly after that it cut out with an ominous Selespeed System Failure message.
He managed to get it up the off-ramp and parked up as safely as he could. The car refused to start.
I arrived, armed with AlfaDiag and a screwdriver, expecting something like a failed crank sensor, or at worst a snapped cam belt.
Nothing particularly interesting was found by AD though... A CAN bus error and an 'engine speed implausible' fault on the Sele ECU, but nothing at all on the engine ECU. Clearing the codes didn't perform any magic, but at least they didn't come back.
He'd already warned me that he knew that he was low on fuel (after dismissing the pumps at Asda due to the length of the queue). Although the gauge was still reading a bit, it was the obvious thing to try. So after a trip to the filling station, we sloshed a couple of gallons in...let the fuel pump run a few times....and it started first time.
I guess the engine speed fault code was the Sele ECU getting very puzzled why the clutch was turning when the engine wasn't...or something like that.
His fiancée was very understanding. A lot more understanding than my Mrs would be anyway!