Ok well I drive a 1988 Chevy Camaro. Whenever I drive the car for under an hour I have no trouble accelerating or decelerating and I can get it up to the 80s and 90s without trouble. For the last 6 months or so whenever I have been driving from anywhere to 1 hour-1 hour and a half my car will slow down around 60-75 and it will become incredibly difficult to speed it up any more than that. If I keep my foot at a certain angle it will maintain a constant speed and eventually accelerate just a bit. But if I push down on the gas any more the car will choke and slow down until I release my foot back to the previous angle. The first couple of times I would stop on the side of the highway wait like 10-15 min and then start it up again and it would run for a while until the same problem occured again. Recently it has been doing it more often. We took it to the Chevy dealership but they didn't find anything and we thought it may have been some sort of temperature sensor but that wasn't it either. I've tried looking around other sites and most people have suggested that it is most likely the fuel pump/ fuel filter that is causing this problem. We changed the fuel pump less than a year ago, so is it possible for it to have gone bad that quick? Also the car doesn't have a catalytic converter, if that even matters. The last time this was doing this too me I looked at my gas tank and was half full and I stopped to fill it up and then the problem went away until it reaccured and when I look again it was once again when the fuel levels were down. This makes me suspect that it is a fuel problem but I want to hear for sure before my dad and I go through the work of taking out the gas tank. Any help would be much appreciated, thanks!