Strange idle problem
 

When the car is idling it is at 1100. But if I pen the hood and leave it open a few hours it idles at normal rpm. Than while driving I'll push the clutch in and the rpm's will rise. I have replaced the IAC valve. It has a Diablo sport tune. The car does have 100,000 miles on it. IT also running extremely rich

i had some simmilar issuies with my idle. i sprayed cleaner in the throttle body and when i started it up to let it run through you would not believe what came out of my exhaust it was so dirty in thier. and once i did that it idled so good and evreything. prolly not your case but just thought id put it out thier see if i could help

Is the car modded at all and is it tossing codes for running rich? It sounds like you have a few issues that need to be taken care of.

if it's rich it's not tuned it's fucked up. Get it to a tuner, make him fix the tune. Don't try to fix the tune yourself. The idle issue is also in the tune. Probably an IAC duty cycle setting or something.

don't know if you fixed it yet but also try cleaning and checking your MAF inside is a little wire just be carefull not to damage it spray it cleaner and use q-tip to wipe it, again very soft so as not to damage it