So I have been deployed elsewhere for the past six years and my 91 RS pretty much sat in storage at my parents. over the years when I got the chance to get home I have managed to keep up with basic maintenance like oil changes and my dad would start it and let it run a few times a month. Now that i'm stationed close to home I have it in my garage. Now it starts fine but idles very erratic when cold. When it warms up it calms down but still every 3 to 5 minutes the rpms jump up to 1500 rpms, when it does their is a loud hissing sucking noise. After driving it for a little while It tends to want to stall, and if it does it wont fire unless I have the gas pedal to the floor. at WOT it bogs and stutters. In addition the AC runs even when its "turned off". I have no idea where to start. The distributer is pretty new, so is the fuel filter. the injectors seem to spray fine. I have a new set of plugs and wires not put on yet. but the old ones on have about 60k on them. the cap and rotor is kinda old to. as far as the ac I have no earthly idea. i'm in FL so i'm not horrible bothered about it being stuck on, better than off...any help would be awesome..

 

Check the fuel pressure, it should be 9-13psi. Auto zone should have a specific tbi tester to rent.