Join Date: Jan 2015
Location: Northern Indiana
Sounds like you've spent a ton of money trying to solve this problem! I would look into a timing issue at idle and I'm sure others that know about this issue will respond. I've spent a ton of money myself to solve weird issues on my Mustang. Just not your issue. You seem to be determined to fix it!
65 C Code hardtop from California still wearing it's original paint.
Roller 331, TW 170 heads, T-5z, FiTech EFI, FPA Headers, Arvinode exhaust, SoT Bilstien coilover front suspension, TJ on eBay 8" 3.40 Trac-Loc 3rd member. Mustang Steve 2008 GT bracketed 12.4" front disks