well i got my car to pretty much run great except for the damn surging. when i first start it up or drive alittle ways it surges from 650-750rpms then when i drive it for along time it surges from 500-1000 rpms. Ive set the idle adjusted the iac cleaned the iac and throttle body. All vacuum lines are good ran seafoam from it (pcv vacuum line) put different fuel injector cleaners and it still surges what is causing it to run like junk?

 

If you havent had it tuned..........Get it done. I had my car on a dyno and they tuned me up for $185.00 ($100.00 for the dyno time $85.00 per hour for tunning).
I would check your fuel pressure, maybe the fuel filter. Its got to be air going in, gas, or air going out.