Hello after reading numerous post about the 3.4 swap I replaced my 2.8 with a spun rod with a new .030 over 3.4 with a 260 dur cam1.6 roller tip rockers, 3.4 injectors and Pacesetter headers. I finally finished the car was completely stripped and rebuilt and have only put 10 miles on the car but it’s running rich.

I was told ahead of time that it would due to the cam and increased displacement so the ECU is thinking it’s running lean so it’s compensating. Come to find out it has the crappy ECU that has a UV chip and can’t be tuned so I was told to switch to the 7730 ECU but after researching it would take a bunch of parts. So can someone help with ideas on what to do. Car feels peppy but from 40 on it’s a slouch maybe due to the richness. It has even thrown a 45 code with is running rich. I also pulled a couple plugs and are black. Please help.

 

The '7730 ECM also uses a UV erasable EPROM. Both ECMs are capable of being tuned. In the stock ECM the injector flow rate needs to be changed.

The other thing that can be done is to install the stock 2.8l injectors. It will lean out up top but at least it won't be dog rich.

RBob.