[asshanson]

You're saying your "840"cc injectors are acting like 546cc on pump gas? That means they need to flow > 50% more gas to run e85 correctly, which is not the case. Have you logged your fuel trims to verify they're around 0 with that -17% correction? I did some searching, and almost every post says that 850cc injectors should be around -31% on e85.