I just had a quick question for the forum. My 92' GT is having an issue that I am having a problem tracking down. It starts fine and runs pefect until it gets up to temperature. Once its at temp it acts as though it is missing or a couple of cylinders aren't getting fuel or fire, but there is no backfire. Because it only happens once it gets to temp I assume its not the fuel pump, injector or a vacuum leak because that would appear immediately. Any suggestions would be greatly appreciated. Thanks.