Long story short, was SC and went back to NA with very mild bolt-ons that I had laying around. I have a Walbro 255lph from my SC build still in the car (using the stock fuel rails and injectors)... I finally started putting some load on the new engine, and plumes of black smoke come out the back if I get on it (not even WOT, just 75% in 4th at 3.5k RPM and quite a bit still comes out).

Do you think the 255lph is creating too much fuel pressure during heavy acceleration? Should I get a fuel pressure regulator, or simply put a stock fuel pump back in?

The car has high flow cats, Motordyne Intake and Plenum, and NO tune.

Thanks!

 

Tune should help...I'd never swap parts like that without one.

 

Its probably running a little rich with the extra fuel its getting.
Just get it tuned, safest option.

 

Well, driving home over the weekend after my experience with the black smoke, I threw Bank 1 and Bank2 / Sensor 1 codes... a big thread on this gremlin here: https://my350z.com/forum/engine-and-...from-hell.html

This is going to be a nightmare.

 

Subscribed

 

I will post updates in both threads... car goes in Friday to the person that threw in the new motor.