Patrick,

As I understand it, until the engine is all the way up on the fuel, I believe its primarily the started motor that keeps it spinning. Also, an over temp. situation occurs when there is too much fuel vs. air (i.e., vs. RPM). Thus, I would agree with Carlos' suggestion as one of the first things to suspect. Your starter motor is probably not keeping the RPMs in pace with the fuel ramp up and thus you're getting over temperature. Certainly, your electronics didn't change, the motor runs normally after start, so the motor seems to be OK, as does the fuel system. Perhaps the starter battery may also be giving up the ghost? Maybe try a new battery pack on the ECU/starter motor before replacing the starter motor?

Bob