That shouldn't happen unless the new scv is faulty or you got loads of air in the system
check the fuel filter is full, fill it if need be, check there's no leaks etc.
If needs be swap the valves back to the old ones.
Usually new scv and prv from Ford carefully fitted will see the van instantly running and better, then updates to make it spot on.
Anything less is operator error
56 350 2.2 130ps mk7 with 2 side doors
65 290 2.2 125ps custom with 2 side doors
07 350 170ps
Ids v86 licence + v86.04 update + xprog
hereIds map
here