I have a 71 220D I am having an odd problem I can't figure out. The car starts and idles just fine. I let it warm up and then head home/to work. When I get to the first couple stoplights it shakes horribly. exhaust sounds bad.. feels like it's "missing" not running on all 4 cyl. then after you drive a little the problem goes away.. injector maybe??? I am at a loss