brake pedal has no pressure engine boggs

[Noh0nda]

i have a 1989 240sx ka24e automatic and all stock.the brake pedal has no pressure it just sinks down. and when im pumping brake trying to get pressure the engine boggs down. also i have to drive like 10 mph because the brakes do almost nothing. the brake fluid is full and the level of fluid never changes

[Shadowgundam'93]

I don't about the engine bogging, but I would check you master cylinder/brake booster first. It sounds like it may have gone out, check all your line connections and ensure there is no air in the brake line by bleeding them if necessary.