[69BahamaYellow]

All excellent ideas; I'll have to test some of them tomorrow. I didn't initially suspect the fuel pump or float levels, as the car runs so good above idle. Full throttle gives plenty of power, with no flat spots. I suppose the problem could very well be too much fuel pressure or too high fuel level in the bowls. This kind of makes sense, as the backfiring and slightly black smoky exhaust makes me think it's too rich at idle. The schematics, tech data and pictures in the Zenith link are great (Thanks for providing this Gary?) I checked out the links by A Quiet Boom, and there does indeed appear to be a lot of good stuff here. A couple more questions for those "in the know"

1) What should the fuel pressure be for Zenith carbs? My fuel pump is not factory, so perhaps it is too much.
2) My idle jets are absolutely clean, but perhaps a previous owner drilled them out too big and I didn't notice. What size hole should be in these things? One of the threads suggested .65mm, was I reading that right?
3) This 2.2 T engine gets 31mpg on long trips @ a steady 65-70MPH. It gets about 12MPG when I drive it really hard. Has anybody else had similar experience with the highway driving? From what I can tell, these engines average about 15MPG; am I just lucky to be getting such good highway mileage?