I have a 1980 280zx which was, when bought, running fuel so rich there was a cloud coming out of the exhaust. Thinking I had an engine issue, I swapped the engines with one functioning perfectly out of a rusted body. The engines were exchanged with intakes, etc. complete.

The condition immediately reproduced itself with the new engine. A mechanic has found and fixed a blocked fuel return line, replaced all the pigtails on the injectors, and checked all the sensors. The car will now crank and idle well for a short time, but soon gradually reaches a rich state that fouls the plugs and all that other jazz. It will run well at high RPM after cranking, then starts loading up when idling.

Any ideas would be appreciated, as well as the correct electrical testing values for wiring and components. Thanks.

BTW, would I be better off putting a triple carb setup on in the place of the fuel injection?

 

Have your fuel pressure tested. Replace the fuel pressure regulator if needed.