Two days ago the engine started cutting out, like there was a sudden interruption in the flow of fuel. It only lasts a second or two, and then it runs fine. It will do this 3-5 times in a mile. I replaced the fuel filter..no change. Fuel pump is brand new (but not OEM). If it's related, the choke doesn't seem to do its job as well as it used to (this problem started a few weeks ago). Whaddaythink?