Car turn over slowly and hard to start

My car started just fine until I replacedte radiatorwith a new one and a new heater hose nut nowit turns over slowly like its not getting a spark, sometimes I must tapp the gas pedal then it does start nut real crappy until I floor the gas peddal then it staraightens out and runs great oh I recently replaced 2 spark plugs nut didnt gap and im losing coolant nut car isnt getting hot or smelly and no fumes from pipe so my wayer is slowly going sokewhere but cant find leak, why hard start?