88 80Q, Runs rough upon starting//possibly resolved

[Huw Powell]

> Turns out the brake booster is bad... Leak changes with pedal application.
> Thinking the booster was bleeding completely down and upon startup the car
> would run alright for a moment, but the vac demand and leak were too much
> for the system.
> 
> Plausible? Seems to start and run fine with line pulled from booster and
> plugged.

Yes.

The "not a problem" version of this you sometimes see is the engien 
stumbling (due to leanness) when the brake pedal is pressed just after 
starting.  Rare, but can happen.

The brake booster is a big "vacuum leak" if it is bad.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/