I am relatively new to TBI tuning and have been doing some trial and error programming with my 1228747 ECM. I am fighting a surging deceleration right now, but there are limited IAC-related scalar values dealing with DFCO available to modify in the current 1228747 xdf. I was looking through the current 7747 xdf and there are a lot more values available to modify, so I thought why can't they also work for 8747? Using the current 7747 and 8747 xdfs, a few stock 5.7L manual transmission bins (mostly because its similar to what I am running), and Mark's post on 7747 IAC Operation (http://www.gearhead-efi.com/Fuel-Inj...pdated-12-4-00) I started copying over IAC scalars and readdressing to match the 8747 bin. I found a 20 byte address offset between 7747 and 8747 bins (8747 shifted down 20 bytes for some reason?) requiring all of the byte addressing to change. I started at the top and worked my way down and most everything matches up (see attached spreadsheet), but there are a few that I highlighted that weren't quite right. Is there other documentation somewhere with all of this addressing, either for the 8747 or 7747? Because these two ECM's are so similar, is this even possible and just hasn't been done yet or am I chasing my tail? Would you guys look over this new xdf and see if I'm on the right track? I would really like to update the 8747 xdf to include as much information as the 7747 does.
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