hessmess wrote:I have been meaning to mention that after the 3.4 conversion you may want to pick up an ECM from a Rodeo that had the 3.1 in it. It will plug right in. It has wider parameters for the sensors. If you start throwing engine codes for no good reason this will usually get rid of them. Also one from a Chevy Lumina van with the 3.1 will plug right in. I can't remember the number. I will look at mine after awhile and see if I can see the number. The 2.8 will work but the 3.1 computer is just a tad better.
A while back before I started the swap, while trying to figure out the best setup, I chatted with Geoff about using the 3.1 ECM, but he said that with the 4.3 TB and injectors, it would over-fuel.
But on an interesting side/related note, I did see a chart recently that had the lb/hr flow ratings for different GM TBI injectors. What stuck out as interesting was that the 305 V8 was rated at 40lb/hr - lower than the 4.3 (45lb/hr), but higher than the 2.8 (33 lb/hr). But, unfortunately after further research, I see them referenced other areas at 50 and 55 lb/hr, so like all things on the internet, it's impossible to know for sure.
Seems like many people who have done the swap report that the 2.8 injectors can't keep up, and the 4.3 injectors over-fuel a bit even with the 2.8 computer. I think for those keeping the 2.8 injectors, the 3.1 ECM will help with the fueling. Should I experience symptoms, and if I could confirm with an expert that they were 40lb/hr, I'd look into them, potentially paired with the 3.1 computer.
I'm hoping to eventually have a rock solid reliable setup with as much power as I can squeeze out of it without eating into that reliability. I'm starting with the 4.3 injectors and stock ECM, and will go from there. Thanks for lookin' out!