Fildigger, mine raises the idle 100 - 150 rpm when the compressor kicks in. As you know, the PCM varies idle speed depending on engine temp, load from power steering pump, alternator, etc. but I think under normal circumstances "baseline" tickover is 750 to 800rpm - so if you're seeing 1700rpm from a warmed-up engine then something's wrong. The only time I've seen more than 1100rpm was when I had a dirty IAC. Cleaned it up in five minutes and things were back to normal. I know you said you cleaned yours but you might want to try again and make sure to do what twostep1n2 said and clean the seat that the cone seals against. On mine, however, it was actually the shaft that had gummed up. Carb cleaner and careful scrubbing with a small brass brush fixed it right up. Oh and I sprayed some contact cleaner on the connectors. Hopefully that will do it for you but if not, your next step would be to break out the propane and look for vacuum leaks. Hopefully it's a hose or faulty PCV valve - and not the infamous intake manifold gaskets...

It definitely needs to be fixed before you ram someone! Let us know what you find.