Hello, have a question maybe someone has the answer. My 91 Z-28 runs fine at idle or part throttle but when I open the trottle fully black smoke comes out of the exhaust. During normal driving there is no smoke only at full throttle. Any ideas of what could be causing this or what to start checking first. I have put new plugs, msd wires, msd coil, msd rotor, and msd cap and the timing is correctly adjusted. It does also kick on the check engine light when I have been driving on the highway for several minutes, but when I turn the car off and start it back up again the light goes off not sure if that is even related to the fuel burning problem or not but just thought I would throw that in. Any help would be greatly appreciated.

 

First I would check and see what trouble code you are getting.