I have a 2012 E38 L77 403cu with a Harrop FDFI 2300. When I start the engine from cold (20 celcius) it has a stumble just after starting. From what I can tell in the log it commands 13:1 AFR just after start which is when the engine rpm drops. After about half a second it then commands the engine to run 10.0. I have not programmed this AFR anywhere. I have found in EFI live there is an algorithm to detect low volitile fuel which would explain this problem. I can't seem to find this in HP Tuners. Apparently it occurs with longer duration camshafts which I am runing. Any ideas?
I thought someone would have had this problem for sure. What I am planning to do is put the stock Cal back in, modify it in EFI Live and download, re read the cal in HP and then modify with the custom OS I am using. Has anyone else done this?