BTW coiter, symptoms of failed ECU range from bad idle, bad acceleration characteristics (kung minor failure lang like bad capacitors) all the way to complete engine blackout (kung talagang patay yung ECU). It'll just keep on cranking but won't start.

however when you have problems like these, the ECU is usually the LAST thing to check, kasi maraming ibang things which can cause these problems. If you're really paranoid, go to the casa and have them dump the codes. On older cars (1994 or older) using OBD-I (On-Board Diagnostics version 1) you can check ECU trouble codes either via the Check Engine Light (if available) or a simple LED blinker and a jumper. This is what I do. but on OBD-II vehicles you really need a dedicated code reader and only the casa has that...

pero as I said, surplus ECU's aren't that expensive.