You should post some pictures of your project so we can see if we see anything wrong.

When you say you open the secondary side the engine falls flat?

on the DGV you may have to drill out the accelerator pump to
.55 mm standard is usually .35mm The Main Jets should be about
1.55mm Primary and 1.65mm Secondary make sure you use accurate drill bits. Air correction Jets 170 and 190 should work fine.

What is your fuel pressure? your fuel pressure also has to rise with the boost.

Idle= 3.5 psi Fuel Pressure
1 psi Boost = 4.5 psi Fuel Pressure
4 psi Boost = 7.5 psi Fuel Pressure

If you try to run 4 psi fuel pressure and get 4 psi boost your fuel pressure will be ZERO and no fuel will get in the bowl.

Lotus used a rising rate regulator and it cost about $45.00
let me know if you need to know where to get it from.

__________________
WARNING: Bastard Mercedes Builder/Tuner
Sorry if I don't answer your email or questions
I don't check here too often.
I am normally on the 190revolution.net board.
Thanks