1). Go to
www.syty.net and sign up. It will help you solve your problems more than this site will. Dont get me wrong, this is a great site but you are dealing with more than a normal S10.
2). Change the oil & filter NOW! Do it before driving one more mile! Gas in the oil will cause engine failure.
3). Replace all of the vacuum lines. This will make a world of differance in your truck! You have a major problem with it running rich. I bet this will fix it among other problems that you dont know you have yet. This may fix your turbo problem too. You can buy a kit for $65. email
iturgeon@gmail.com . The kit is worth every penny and is easy to install.
4). Change the oil & filter again. You really dont want that gas in there.
5). Replace the plugs ( Delco CR42 or NGK UR6 plugs ), Wires ( Good ones...Taylor or ATR ), Cap and Rotor ( make sure they have brass terminals ) and the O2 sensor.
6). Change the oil & filter again.
Do these things and let me know what happens.