1979 Honda Accord 1979 Honda Accord - Runs Rough

I recently bought a 1979 Honda Accord just for a fuel efficient car to drive back and forth to work. Unfortunately I took it through some preety deep puddles and some mud. I was pretty rough on the car. Anyways when it is driving it runs fine until it gets pretty warm. If your giving it a consistant amount of gas, just cruising, it sputters and lurks. But if you floor it it runs strong. Im running out of ideas on this one and could use some help. The only thing I could think of is the fuel filter is clogged and when you give it consistant fuel or it sits to warm up sediment builds up and clogs the filter. Then when floored it stirs all the sediment up clearing the fuel delivery. Let me know of any ideas. Thank you I would really appreciate it