try this idle problem

[corn322]

when I hit the brake, the idle drops about 200 rpm for a bit, then comes back to normal. could it be a leaky brake booster?

[navysnail]

yes it very well could be

try looking along the lines to the collector for leaks

[S13ChucKAT]

Bleed your brakes.. sounds like you have air in your lines.

[nyckanny]

i have the same exact problem, but it doesn;t happen when the engines warm. when its cold, rpms drop a lot while i brake in neutral. then when i release the brake after stopping, the idle surges up and down from like 500-1000iacv problem or maf, maybe even this brake booster leak?

ken

[frapjap]

My brake booster hisses like a vaccum leak, but I don't get those symptoms. Whats the hissing brake booster mean typically? I don't have any adverse effects while drifting or braking hard.

[corn322]

eh, after many months it sill does the same thing. But it's not a leaky brake booster. it never hissed, and help pressure over night. the dropping idle is just something stupid it does.

frapjap, hissing is a sign of a leaky booster.