This is similar to the situation in the TSIO-xxx, and the fix will be the same, also.  That is, a different shroud is used over the injectors, and air, instead of being pulled in from the ambient air, is ducted to each injector shroud from the intake manifold.  One could either add the shrouds and rails from the TSIO parts catalog,

Jim, Et Al,

 

Be carfeful about the terms you use on this topic.  One may want to tap into the ram air pressure plenum, if one exists, before the throttle body BUT not afterwards from the induction manifold since the air pressures may not be right at anything less than WOT.  Even though I have been using a separate ram air "pitot" to supply air to shrouded injectors for over a year, I am still surprised to see the affects on the mixture when the entire ram air system becomes more effective at the level out and speed increase after a climb.

 

I have not yet blocked the air to the injectors to see if the engine will keep running.

 

Scott Krueger

IO 320