1996 Other Oldsmobile Models security

This car has 3.1 v6, starts and runs great from a cold start. After the car has been shut down after a ten or more mile trip it either refuses to start or starts then chugs, shakes knocks shakes and dies and will not restart. If left for 30-40 minutes will start but needs coaxing to keep runnning, if you get it to rev above 2000 rpm for a minute ro so it will setle down and run normaly. After replacing the iac valve which was broken, problem prevailed. Then replaced tps maf sensor and the ignition lock & thermostat. The (used) ignition lock seemed to solve the problem until the return of warm weather and began acting up again. Put in a new ignition lock this time. This car leaves us stranded everywhere. Last fall I manages to get it towed to a friends garage while it wouldn't start and we scanned it and got security fuel injector shut off. Otherwise the car had no codes before. Reset code and car started fine. Have recently scanned after it srarted having this problem but no codes. Seems to be related to outside temp somehow. When the rough start happens the secuity light is flashing. Any ideas? Keith