92 Regal idle issues

I have a 92 Regal with the 3800 V6, around 100K. I was having problems with the car missing at highway speed, poor idle, hesitation upon acceleration, hard to start... Trouble code 17 indicated a bad crank sensor, which was replaced. This got rid of the miss. Changing some badly worn spark plugs/wires got rid of the hesitation, and helped the car to start better. My remaining issue is an erratic idle. The idle in park and in drive is rough, you can tell the ECM has to work hard to keep it from stalling. If you rev the gas while the transmission is in park the engine will rev up, and sometimes stall after the rpms come back down. It will occasionally start up and stall quickly also. Fuel filter is my next idea to change but I haven't done it yet. I added a bottle of fuel injector cleaner also. Any ideas? If I can't get this running reliably, I'll probably get rid of it...