Stumbles and dies, hissing brakes

[Knoepfler]

So I finally got everything running right and everything working and aligned etc...

Then I went rompin with some friends and it ran great for a few hours no problems and I was almost back home when it started sounding like a fuel cut when I would accelerate and then died so I pulled over and checked everything and found that my hose from the FPR to the intake mani had popped off so I put it back on and started and ran great for another 2 minutes and then same thing started happening.

I checked every hose and connection and ground etc that I could see and they all seemed fine.

I do have a problem with the booster that causes the brakes to hiss when I press them until they're about halfway down then it stops, so clearly somethings not right there.

Could the brake booster problem have just escalated while driving it around and now finally causing such a big vacuum leak that it just stumbles and dies when I try and start it? Also, if I give it gas it dies instantly.

M52 OBDI
Porsche 944 booster

btw these things haul ass ;) do not miss the m42 one bit

parked it in some dudes lawn for the night gonna see what I can do in the morning

[ck_taft325is]

Sounds exactly like the problem I have. Pop the big vacuum line that runs to the back side of the intake (Booster/reservoir side) off while the engine is running. If the booster sucks a shit load of vacuum and almost kills the engine, your booster is fine. Much like mine, it's probably the master cylinder.

[Knoepfler]

Ok switched out FPR and injectors and still doing same thing. When I unhooked the front fuel line it was likea geyser. Im really stumped

[ExViTermini]

Sounds like a booster issue, but to check just take some pliers and pinch off the vacuum line going to the booster and see if she revs up and acts fine, if so, you've found your problem.

[spaceshuttle]

I have a hissing from around the booster to its almost like a wining. It goes away when I hit the gas and when the brakes are applied half way. I have a s50 with a 7 series booster. The sound goes away when I pinch the main vacuum with pliers but thats all that happens. There is also a blue line that was on the original booster it seemed like it didn't do anything so I just plugged it. Sorry to hijack the thread just tryin to figure the hissing out. So any ideas?