Yo the car gets warm and the car dies, because the ecm is choking the engine till it gets to operating temp, while its doing that the engine idle is compromised, so even if the timing or idle is off you wont know until the engine is warm! do you understand? if not i work at S&R Performance, and i drive and s13 i can help you. names JEFF
check:
Coolent temp<----actual temp reading not the sensor
ecu plugs
air fuel ratio
fuel pressure
IAC valve
if no luck pm me or call the shop!! 961-0609