can a vacuum leak in the break booster cause a car to misfire on throttle and run normal approaching high RPM?

specs:
87 rx7 NA
new plugs and new wires
new oil

 

Fix the leak and find out?

 

If the booster has a leak, more than likely you have a vacuum leak. replace the booster, and bye bye leak from booster and should fix your issue.


Wait check you booster lines for cracks or leaks as well, you may just need to replace those hoses instead.

just some suggestions

 

lolz thank you

 

HMMM.
the Brake booster needs vacuum to operate.It has a Check valve so it can only see Vacuum when activated.
That check valve is IN the Rubber S hose at the Booster(attaches to the steel line at the firewall).
So,That would raise the question of whether the Booster "could get" a Vacuum leak..

 

Yes.


Yes it can.

 

if the booster is leaking a simple test would be removing the line from the intake manifold and capping it. if the idle smooths out then you may well have a leaking booster or cracked line leading to the booster.

there should be no need to throw parts at it, a booster will leak all the time but performance and drivability won't be affected under high loads since the intake manifold is producing no vacuum at that time.

the check valve is to keep vacuum in the booster, if the booster is leaking the manifold will constantly pull vacuum through the check valve so that isn't the problem.

i have never seen a failed booster in an FC, so i highly doubt it is your problem.