My truck has started to put out quite a bit of white smoke under light throttle. It starts and idles fine. There is no white smoke at idle or at start-up. However, if you're trying to putt along at like 20mph, its like i'm driving a big red fog machine. If you give it a little more trottle, the smoke turns a darker hue and appears more normal. Any ideas? I know that most of the time, white smoke is indicative of a bad injector. However, if i have a bad injector, shouldn't it be producing the white smoke at start-up and at idle? This is my first diesel so i'm pretty unexperienced with this stuff. Any help is greatly appreciated!