1992 Honda Accord Car won't start sometimes

My car just won't start sometimes. I let it sit for 20 mins and go back and then it starts right up. It is almost like it is not getting any gas. It acts like it is going to start, but just doesn't get that extra umph to start. It's not the battery, I have power when I try to start it, my radio works and everything that is battery powered works, it just doesn't start. I took it to get it fixed and they told me that it was the fuel pump. I got the fuel pump and filter changed, and that fixed the problem for about a month or so, but now it won't start again. It only does it once every few months, and it seems to do it when it is hot outside. Do you have any ideas that will help me? I don't want to get rid of my car.