1998 Oldsmobile Bravada wont start without using choke clea

I have been noticing troubles with the starting. It has been starting hard. I usually have to turn the key on and wait a few minutes and it will start. The other day it took me awhile longer turning the key on and off to get it to start and when i turned it off it would not start again i sprayed carb and choke cleaner in the throttle body and it started up no problem and runs good but wont start back up after i turn it off I just replaced the fuel filter less than a week ago. I beleive if i did it right i checked the fuel pressure at the cap on the line on the driver side behind the throttle body and it read 55. Also another question is it has been smoking white smoke for over a year but doesnt overheat and smells funny is there a chance its a bad intake gasket instead of a head gasket. White smoke is usually antifreeze but i didnt know if the intake port and coolant passages where connected on the gasket