97 Escort accelerates VERY slowly,ecspecially when the engine is cold.Ideas??

You know I put a different engine in the car when I bought it a couple of years ago but I'm not quite sure I ever changed out the fuel filter. I was looking at it today and it looks very clean but we both know that doesn't mean a thing! I'll replace it and see what happens and let you know. Thanks!

In the last few weeks I have had wreckers bring me cars that stopped going down the road with loss of power and several had either a restricted air or fuel filter.