Originally Posted by
cmitchell17
Thanks, I think I will go back and redo VVE and MAF in the non PE regions with the narrowband feedback hopefully it's more stable.
So I have the L9H flex fuel version of the 6.2 truck engine which supposedly has the same FPCMs as the LSA LS9 stuff with some differences, at least I think there seems to be a lot of misinformation and lack of confirmed info on these, since most people mod the cheaper GEN III 4.8/5.3 stuff. I think a lot of people use the stock L9H in tank fuel pump as an upgrade though.
Looking at the FPCM cal it looks like there is a lot of things that could be tried, but most probably have no effect as I don't think the truck flex fuel pumps have the same capabilities as the LSA/LS9 stuff. I have heard people swaping LSA/CTSV FPCMs in the trucks a upgrades, but not sure if the BCM/ECM would complain about a VIN mismatch or anything, don't think so since the GMT900s thankfully I don't think they care about that stuff unless there is a ECM/BCM mismatch of course since I think BCM handles security, or of course radio theftlock as well. But it makes me wonder why I can't just full flash my FPCM to a CTSV OS, but I guess there's probably a large chance of bricking.
I would think I can at least raise the max DC from 90% to 100% but can't find anyone who has really done it and reported improvement. I have heard though you have to add a boost a pump after the FPCM since apparently somehow the FPCM can see the higher voltage and lower it back down.
I say this because I think the stock 6.2 flex fuel system has a lot of potential, and I find with fuel system mods there is a lot of unknown and hacking it seems, which I feel makes the system vulnerable to failing and leaving you stranded.
And how can you get more from the system being boost referenced? I mean I understand it would let you command more pressure based off boost to achieve the same net pressure of the fuel inside the intake manifold, but I don't get what's stopping you from just running more pressure regardless? I guess you would need a physical pressure regulator added to the system anyway to do this, which it would be nice if we could use the already built in functionality in the FPCM to control boost referenced fuel pressure.
I think with a pressure increase, to the supposed pressure the LSA/LS9 runs, I think that can give me significantly more injector flow and room, and time to save up for ridiculously highly priced injectors haha.