Not knowing the injector size makes it tough... but it does actually run you say? If so give me a cell to start from - MAP, rpm, and the base fuel map value from a point where it is running (and warmed up, so any of the startup/warmup enrichments are gone) - and I'll generate something from that. Won't be good, but might be a better starting point than what you have now.
In the meantime, I wouldn't just drop the whole map by 10. At idle this might be a big change, but up higher this might not be much of a change at all. A better strategy is to change it by some %. I'd start off by dropping 10% from all the cells, so if a cell has a value of 10 it would go to 9, while a cell with a value of 90 would go to 81. That will keep the shape of the map, the fuel curve if you will, constant. Assuming you started off with a curve that worked well in another similar car then you won't lose that curve by fiddling with it. If you just add or subtract a given value across the board, then you are changing the shape of the curve, making it a lot richer or leaner at one end while not doing much to the other end.
I don't know if the DFI6 has a provision to change the entire base fuel map by a given %, someone else might know that. If not you can change the just the cells where it is trying to idle, and once it is idling ok figure up the % change it took to do that, then apply that to the rest of the map, then see how it runs in those areas.
Are the injectors stock GM for this engine perhaps? Or are they aftermarkets that someone installed before you owned it? Or you really have no idea, could be anything?
John
