Can someone help me find a solution to get rid of the black smoke that comes out of the tailpipe of my '84 Z28 4bbl? It usually does this when I'm 1/2 to 100% throttle. Is it a rich fuel mixture?

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1984 Z28 L69
Mods: custom body panel dents, 3qts oil (from 5)to save weight, caulked t-tops, oxidized paint, !radio, !muffler, !pwr steering, !rear brakes, !parking brake, custom scratched racing stripes on hood, etc.

AIM: sahlomonic

 

Black smoke = unburnt fuel

Bring down the mix or retard the timing. If its realy bad you may need to find acomprimise between the two.

 

If adjusting the mixture doesn't solve the issue, check the compression. Black smoke can be a sign of a low compression engine.