I have an '84 240 Turbo sedan with a problem I can't figure out; it shudders and loses power and seems like it's about to die. But it doesn't die, just kind of sputters for a bit, usually less than 30 seconds, and then it gets over it and is okay again. I've noticed it mostly when I am going uphill and usually at higher speeds 45 mph and over. Although it has occured on flat ground as well as slower speeds. I've changed the oil, the fuel filter, and the spark plugs and cleaned the carburator with some of that spray stuff. If anyone has got any idea what the problem could be, please post some tips and advice. Thanks.