Also, check the post for 'Alarm System' in 'Supra FAQ'. Here's a quick link:
http://www.toyota-supra.info/forums/...rm-system.html . If you read through it, and look at the wiring diagrams, you'll see that the security system does only interrupt the starter circuit by ungrounding the relay. That's all it does. It does not interrupt the ignition circuits at all. I hope the key trick worked.