Chevrolet: runs poorly, throttle position sensor, quad 4 engine

Question
I just bought a 1993 Beretta with a quad 4 engine 2.3L and it starts with out a problem, but as I'm driving the engine will repeatedly die and restart after I put the key in the off position. I have replaced the fuel filter, do you have any idea what the cause is? thanks

Answer
Jeromy,
     The first place I would probably start is the throttle position sensor. If it goes bad it could cause the problem you describe. If that doesn't fix the issue, then I would check the codes stored in the computer to see if there are any that could help with a starting point. Your car has an ODB1 system, so you can have the codes pulled with a code key, or you can do it yourself. Take a paper clip and with the car off, locate your ODBI port... Driver's side, peeking out below the dash... then take the paper clip and jump the two right top terminals. Turn the key on, but DO NOT start the car. The service engine/check engine light should flash 12 (one long flash, two quick flashes) Then from there, start counting flashes. Long flashes will be the first number of the code, short ones the second. All codes are two digit codes, and will repeat or flash 12 again at the end of the codes stored list. Pull your codes and let me know what there was and we'll see if we can get a little deeper into it. Good Luck!