67 dart stroker hellcat gen3 hemi with twin turbos...
Totally different vehicle, but installed a Motec on a late model foreign job and had issues with it bucking, tach pegging to 15,000+ RPM, and other issues. I worked with their East Coast guru for awhile, sent in the Tune for him to evaluate, etc. The West Coast Expert was then brought into the discussion. In the end it came back off. They charged a 20% restocking fee for the ECU and the harness was ours because I modified it (of course?!?).
Later I realized the issue was that the Cam Position Sensor was mounted on the cam that advances/retards. The Motec was just used as a fuel & ignition controller, with all the other controls (tranny, gauges, even adjustable cam timing) left to the factory ECU. The cam would change relationship with the crank sensor and BLAM! This eventually burned up the cats. Oh, and you think your Holley was expensive, price a Motec!!