Engine Problem

[Stymee14]

My 1984 Supra will start and only stays running if I press the gas pedal. If I rev it up and let off the gas pedal, the car will cut off. If I start it and don't press the gas pedal, it will idle real rough around 600 rpm (barely running).

I normally ran regular unleaded in the car which it ran like a top. When gas prices decline, I put in a batch of Super unleaded. I noticed the car hesitating shortly afterwards. Now, it's to the point if I drive it and stop at a light, once I take my foot of the gas pedal, the car dies! I have to restart it, constantly give it some gas to keep it running.

I didn't want to waste time and money and was hoping someone had a similar problem that could turn me on to a fix. Do you think sediments/water may be in the gas to have partially clogged the fuel filter or some of the fuel injectors???

I ran the Super unleaded out to a 1/4 of a tank then refilled it with regular unleaded, dumped some STP gas treatment in the tank the last fill up.