If your brake pedal is stiff and it stalls when you apply the brakes it sounds like the diaphram in you brake booster may be ruptured. If the booster rubber diaphragm or system check valve are damaged this will provide an unwanted path for the engine vacuum to leak out.
Holley Ultra Engine Stalls Hard Braking Club Cobra
Engine stalls when braking hard. Common symptoms of stalling when stopping. The car runs fantastic in all rpm ranges. Thus causing the same thing as an intake manifold leak. The car may also stall due to a vacuum leak in the anti lock brakes system. Stalling can also happen if there is a brake line obstruction either by a chunk of rust or a pinched brake line. Under hard braking revs would drop 4 500 rpm.
This occurs when the diaphragm inside the brake booster fails and allows air to bypass the seal. If it doesnt stall then its time for a new booster. Air in the brake fluid from a hole in the system can prevent proper pressure to the brakes. Do what steve said and pull the vacuum line to the booster and cap it off and see if it still stalls. Engine stalling problems can be hard to find and are often sensor or temperature related. I suspected fuel sloshing from the rear bowl and flooding the engine so i connected both bowl vents with a piece of fuel line.
I have set the float level from bottom of the sight glass to 34 with no apparent change. 274 0 0 0. The brakes are then pressed the engine feels like it will stall and the idle can drop. Engine stalling is more likely to occur during cold weather or when starting a cold engine. Chevy trailblazer stalls when stopping or braking hard refers to when the engine stops running as a result of applying the brakes and coming to a stop. First make sure your 4 corner idle mixture screws and curb idle speed are set properly.
So this kind of engine stalling problem often means the engine is not getting enough fuel andor too much air. The only issue is stalling. Then adjusted the primary float level up 2 flats loosen the locking screw and rotate the adjusting nut counter clockwise 2 flats this has significantly improved the situation. Engine stalls when brakes are applied when the brake booster is failing it can draw excess vacuum from the engine. During hard braking the rpm drops and stalls.
Gallery of Engine Stalls When Braking Hard
