I have a 76' 280Z, with the original L28Ein it, it recently failed smog, for running extremely rich. Not only that but it started giving me more problems once I got it back from the smog shop.

On the way home from smog the oil pressure was very low, I want to say around 15 Psi, oil level is fine though. It was checked the next morning after it had been sitting all night long, and currently if I drive it around the Psi level is normal.

The next thing though is it smokes a lot if you rev it at all, or under normal driving conditions. Around 2500+ RPM. The smoke is white in color.

It will also shoot black "soot" which I can only assume is carbon build up from inside the motor, out of the exhaust.

And finally some mornings when I start it, it will be misfiring and not hold an idle, I'm not sure of how many cylinders it's missing on. But it sounds like 2ish.

If anyone has any insight on this, all help would be appreciated, thanks.