Rough idle, surging in gear

Hi, I have a 90 Cutlass Cruiser 3.3 and it started idling rough lately in gear. When I'm in DRIVE and take my foot off the brake, its really bad, kinda surges forward. When I step on the gas its smooth. It also runs bad at higher speeds when I barely step on the gas. I gave it a tuneup, plugs, wires, fuel cleaner, cleaned intake with carb cleaner. What else to do??
I need to replace PCV. How do you check the coil? Also, where is the fuel filter? How do I check for codes?
Thanks lots.