I don't drive my 1970 1800E very much in the winter, but I do start it up every few days.

About a week ago it would not start, so I went through the routine of checking for fuel and spark and discovered that the plugs were coated with what looked like soot - very dark. I replaced the plugs, and it started right up. I did not drive it since there was about a foot of snow on the ground, so I let it run a while in the garage. I did notice that when I let off the accelerator after revving the engine, it would backfire through the exhaust. It had not been doing that.

Today, I cranked it, let it warm up, and started to drive it around the block. Whoa! Black smoke coming out of the exhaust, backfiring when I shifted, and it ran so rough I coaxed it back home and parked it in the garage.

It idles great, smooth as silk (after it warms up). I checked the timing and it is right on the mark.

The Chilton's book says something about an auxillary air valve, but I really don't want to spend $350 if there's something else I'm missing. Any ideas would be greatly appreciated.

Thanks!!

Dan B