[Getter-Done]

I just noticed in the picture the secondary butter- flys are Open. They are suppose to be closed at idle and normal driving until loss of vacuum (When You put the Pedal to the Metal). The White diaphragm behind the fuel filter takes care open the rear top flaps when the Throttle is push to the floor. The screw between the Rear Butter-Flys adjusts the manuel linkage. Some thing may be in a bind with this linkage or proper vacuum may not be supplied to operate the diaphragm.
If you check these two things you may find the problem.

Hope this helps