Hard braking causes car to force stall

[mikinoz]

You need to remove it from the brake booster and plug that end as you need the manifold bit connected for other vac lines.

I just removed a working one from my mk1 if you are looking to buy a different one, I upgraded to a larger diameter one.

[huss]

Ooooohh I see what you mean mik, I had the wrong one plugged. And thanks for the offer but I've basically got the same setup as you and I prefer to use the larger diameter booster as well.

So I plugged the manifold bit as suggested above, as expected the brakes were harder to step on but it made no difference to idling if I was stepping on the brakes or not. (I tested this stationary, not moving)

I should make this clear, the car only cuts out when stomping on the brakes when Im driving, when stationary I can stomp all day long. But when stationary and I stomp on the brakes quickly the engine stutters a tiny bit.

Also when driving and I stomp on the brakes I noticed if I stomp hard, then release then stomp again, the engine just survives. So when I feed the brakes once or twice the engine stays alive.

If im blabbering on like an idiot and not making sense just tell me

[AUC-05L]

Its not a booster issue.

If you are running a 32/36 weber, than what you are experiencing is fuel surge in the bowl. I had this as well, used to surge when turning right and decelerating and as a result it would stall. Its because the 32/36 weber wasn't designed to run on a transverse engine.

There is no real way around it, as I had mine professionally tuned and it still did it. Had to change my driving style (keep it in gear longer). got used to it after a while.

[richo]

2nd the last post. i had a 32/36 and surge caused it to stall on hard braking. the guy who tuned it up for me said it might be a problem as the way it was mounted (transverse) was not what they were designed for, or something or rather. i had to change my driving style.

[huss]

Im starting to think this as well, since I performed a few tests on my brake booster and it didnt seem faulty.

[huss]

Had a chat to my mechanic friend, He reckons that since I upped my booster size, got bigger front calipers and rear disk brakes, And since Im still using the original 1.6l motor. That I am probably sucking most of the vacuum out from the intake manifold and into the booster. Thus giving me the answer as to why it tries (and sometimes succeeds) to stall when braking hard and driving, and it doesnt stall when braking hard and im idle.

Probably just need to get a mk3 engine in (which I was planning on doing). Hopefully that will fix it.

What you guys think?