When I repeatedly pump the brake pedal my engine stalls. No pedal pressure

Did you replace the booster.

Bleed the air from the brake system!!

Check your vacuums from your brake booster. Sounds like it's drawing vacuum from the engine and causing stall. Mine did that. I have a 1992 Isuzu Pup, Carbed 2.3 (Original Hitachi) with a 5 speed.