remove both front suspension units and disasemble them - you may be experiencing someones genius attempt to cheaply fix a problem by installing one spring when it broke etc. Springs should be replaced in pairs ideally unless if you are dead sure that you are getting a proper replacement item then one can work.
Get some used springs as a set and test the damping action of the shocks when out of the car, they are gas charged and should rise themselves on pressing down, their reaction to sudden pull or push should be very difficult to achieve. If its soft on either way or are jamming (bent) they are scrap and also a driving safety hazard