Car won't start after a short trip?

I have a 93 camry (auto gear) with 230k miles on it. recently i started having the problem of starting my car. it almost always happened this way - right after a short trip, less than a 10 min drive, i had to completely shut off the engine. then if i were to restart it within 10 min or less, oftentimes the car wouldn't start. a few times i kinda pressed the gas and engine shot up to 3000 rpm. if i released the gas, engine died either immediately or right after i shifted gear to D. if i kept the gas pedal pressed for a while and the engine was running at 2-3k rpm the whole time, a few minutes (?) later when i released the gas, engine could stay on. the most recent episode, however, engine wouldn't start (i heard the crank and lights on the panel were all on) and pressing the gas did not help either. i ended up shifting the gear to neutral and then miraculously (or coincidently) engine started when i turned the key while also pressing the gas. i recently had the engine "tuned up", but seems that the issue of engine failure to start persists. any idea?? and how i should respond when the engine dies in the middle of the road (or anywhere else that would block the traffic). any suggestion will be appreciated. Thanks a lot