I had a problem with the screen wash pump on my fiat coupe, the water was only trickling out of the front jets. This can be easily sorted by removing the pump from the bottle( just pulls out & remember to empty bottle first !) and the rubber seal/filter that the pump fits into and give them a good clean as slime and gunk from old screenwash etc builds up over the years !. once clean put back together and should be sorted !.
jamie b
November 2008