HELP! Anyone have this 355 idle issue?

Been enjoying the car for awhile now but lately have a really disconcerting idle issue and was hoping someone could clue me in to what's going on: AFTER the car is up to temp and I've been driving around for roughly 30min plus I get an intermittent (not every time but occurs more times than not) problem. When driving around town and coming to a stop the car will: a)hang up around 2000 rpm or so b)dip down to around 850 rpm c) dip to 850 rpm, then if at the light long enough will recover to normal or go up to 2000-ish rpm. SOMETIMES coming to a stop will be met with a normal idle speed but even then (if the stoplight is long enough duration) one of the listed issues will occur. sometimes bliping the thottle will cure the particular instance but only for that stoplight. next light/stop sign it happens again. Also (not sure if it's related but thought it worth mentioning) the car seems to run insanely hot at shut down. I shut the car down after doing some errands and out of curiosity, turn the key back to the position where the gauges came back on. Then watched the temp gauge in the cluster over the steering wheel climb to within one 'tick' of the red mark before quickly turning the car back on to help cool it via heat exchange with fluids flowing again. Thankfully this worked and got it back to 190 again. Is this normal? Am I obsessing about the temp for no reason? First Ferrari (always porsches before--with run down coolers and fans that stay on after shut down) so don't know what's 'normal'. Thanks in advance to anyone that can shine some light on this issue for me. btw 96 355gts hyperflow/tubi set up but no other mods. Love the car and desperately want to fix this so I can return to using it as my daily driver.

 

First of all, Thanks to you guys for the help. I will investigate the things suggested. As for 'both fans coming on'...ok..well, I know I'm going to sound like a complete idiot here but where are they? I hear the ONE fan in the drivers side air intake..is there another one for the other side or is it in the front? Do they come on at the same time/should I hear both is one is on? Like I said, a sincere thanks to everyone for their help on this.

 

Thanks will check today on the fans. have apt. at local indpend. svc place for other stuff....check writing hand already getting a cramp-lol