idling problems

With the belt on the steering pulley won't turn.. without the belt mine turns pretty easily (from what I recall when I had it off last.)

I'm not certain how this pertains to your idle issue.. but have you tried cleaning the IAC and the TB? You may also need to reset the base idle while you're at it.. I guess the main question on my mind is what caused it in the first place.

if it doesnt idle right check the throttle position sensor. i don't think that by changing the belt tensioner would make your car idle bad.

Also take out the air by pass valve and clean it with some carburator cleaner, may be that would help to idle better.

See the "Help me create the Surging Idle Checklist" " Sticky at the top of the forum for help with idle problems.

The PS pump pulley should spin pretty easily (you can feel yourself pumping some fluid, but it is not disiimilar to the alternator in terms of resistance IMHO). I can hear mine make little clicking noises as the vanes turn.

It is not at all normal to have idle issues after doing a serp belt. I would really go over every single place you were touching while doing this. I get on a thrash and disconnect or disturb things (that I did not realize I disturbed) and forget to recheck or reconnect things.

a 5.0 motor does not change the IAC duty cycle to accomodate engine load from the PS (like smaller motors do), so I doubt that is an issue.

Good luck.