Pontiac Bonneville sse 1990 140k.
after i drive tha car about a mile i get the coolant tep light ON even the gauge termometer shows about 140F.
the car runs OK.
sometimes after continuing drive the temp light goes OFF.....
park the car for the night - in the morning i have a hard start problem. i will start the car after a few cranks then i need a minute to run on parking to get the engine running with a normal power...
any suggestions? Thanks.

the reason most likely the coolant lite goes off while driving is because enough air passes through the rad to cool the coolant off. check thermostat, try flushing(use HIGH PRESSURE) the rad and putting in new good coolant, check coolant level, etc.

hard start could be many things. failing starter, failing battery, etc. i'd say spark or inj but when running it's fine. it also sounds as if it's heat related being that when it sits all night it's hard but i assume when it's warm/just used it starts easy. as with most old car this is the same way. honestly you probably just need a new batt. every time i'v replaced them in older cars they start up much better as the starter is getting all the 'juice' it needs. if that doesn't fix it try re greasing the starter and while you're in there, check it out obviously. i'm sure someone can link you to a writeup of how to do this and what to look for while you're in there and how to regrease grease to use/where to buy etc. or buy a $5 haynes or chiltons...

--goodluck

p.s. try searching it's a wonderful tool.