Engine cut out

[Rich28]

I have had problems with erratic revs and engine cutting out at low speed and idle on a 156 1.8TS Cleaning the butterfly valve seemed to cure it but 2 or 3 months later it came back so I cleaned it again but it doesn't seemed to have helped this time. Any other ideas what could be causing this?
Also while I'm on, the rear windows keep dropping a couple of mm just enough to let wind noise in can I tighten these up anywhere? And..., last one I promise, is there anywhere I can lubricate to stop the suspension squeaking so bad?

Thanks
Rich