SR20 Runs like crap, need help.

[89Turbo]

ok so my buddy just picked a 91 Coupe with an SR20DET in it from a towing yard. At first it would not crank over at all. We changed out the plugs and it immediatly fired up, it also needed a water pump, and belts which we already did also. once we get it started though the RPM's jump from 2500 to 3000 in a perfect 500rpm increment. We let it run for 10 minutes it got a little quieter as time went on but still idling super high and rough. Now we also noticed that there is a pretty bad exhaust leak which we can hear and think its coming from the gasket where the turbo meets the manifold but its not bad enough to cause this. What kind of problems can you throw out there for me to look into? Mass air flow, check for major vacuum or boost leaks, but what else? oh and we didnt try driving it like that becuase there is major snow outside.

[ho1ywars]

any codes? coolant temp sensor, maf, and vac leaks..

[Blown240sx]

TPS could be off (.45-.5v fullly close is factory spec)MAF could be bad (unhook it to check) (1-1.2v at idle)IAC could be bad

Id say those would be the main problems.