Cannot start car - ford fiesta 1400cc 1992?

car turns over fast , just decided not to start, checked the connection under engine, ,cleaned tubes of( like custard ) in tubes to filter , do not appear to have a fuse 19. still no start , any ideas please , thank you .I put a new alternator on ,checked with supplier ,correct one, I used the car a couple of times
it ran o.k. did stall a couple of times other than that it was fine until next day.