imported_loudsubz

It seems that lately my idle has gotten a little rough when braking, in the morning when the car is still warming up, if im driving somewhere and then have to stop for a red light etc, i slow down then release the clutch and the rpm drops and idles around 900-1000, but when I apply the brake it drops to like 500 and the engine shakes a bit more like its gonna stall.

this doens't happen as bad as when its been warmed up for awhile, the rpm will still drop a bit bot nothing that makes me worry about the engine

Car is 94 LX, engine is 99 Y8.

bbarbulo

iTrader: (2)

you, sir, have a vacuum leak somehere... hook up a vacuum gauge, if the needle is all jumpy, get the rubber hose and clamps out, cuz you're replacing a bunch of lines...

imported_loudsubz

thanks B, where do you connect the vaccum gauge too? And can these be baught at like CT etc?

bbarbulo

iTrader: (2)

Ya, any vacuum gauge will do (I got a Walmart one for quick tests, and I got a nice liquid filled industrial gauge for more involoved tests), and you hook it up to any line that goes to your intake manifold itself... like the big booster vacuum line That's what makes me think you have a vacuum leak, cuz you press your brakes with the engine at idle, and you take a lot of vacuum, plus if you have a leak somewhere, it'll make the idle drop big time.

DanielM

got any pics to where this vacuum line is? there's so many hoses and I don't know which one is what.

bbarbulo

iTrader: (2)

doesn't matter which one you test.... it all comes from your intake manifold, and fluids behave so that the vacuum in one will be = to vacuum in other unless there are check valves in the way.

red90dx

check all vacuum lines as B said, I use my fingers and run it along, also check out the eacv at the back on the intake manifold to make sure its #1 plugged in, #2 its getting a signal, and you may have more success cleaning it out with t/b cleaner, or injector cleaner.

DanielM

if you disconnect the brake hose and replace the hose will air get in? and do you have the air out the system?

DanielM

the brake hose that is connected to the intake manifold that is.

bbarbulo

iTrader: (2)

no man... it's the vacuum hose to the brake booster, not the master cylinder.

DanielM

so will that get air in it?

bbarbulo

iTrader: (2)

air is supposed to go in the brake booster... it won't get in your brake lines if that's what you mean... power brakes work off engine vacuum, which is why there is no power assist if the engine isn't running.