thejimsterz28

Hey guys I was doing a research on brake boosters because of my wandering idle, like erratic bad idle once it warms up. I've replaced iac valve and set it and all that. My brake booster makes a high pitched whine when u apply the brakes sometimes, and if you turn the car off while it's whining, you hear it slowly fade away. Could this cause my idle issue? Also, do the tpi cars come with that booster filter? Mine doesn't have one on it.

foxxtrot82

I also have a 91 350 tpi Camaro. It doesn't have a booster filter on it. Check ur egr valve operation. Suck on the hose coming from the egr. Place ur finger under the egr, its located under the plenum. tight fit. The diaphragm will move upward and hold until u release the pressure. mine was bad and didn't know it. I had bad up and down idling when it got warmed up. it could've been sucking fresh air, and it stumbled off the line everytime unless u floored it. the idle isn't perfect now, but its a lot better. I believe my egr solenoid is constantly flowing. I will check it sometime or other. As for the whining sound coming from the brake booster, it sounds like it could be air. remove the hose from brake booster and cover open end of hose. no sound should occure. if the booster is leaking air, then extra air is entering the system which is considered a vacume leak. good luck.

thejimsterz28

Thanks! I'm going to unhook my vacuum hose to brake booster and check. As far as the egr, it's deleted along with the smog pump. I'll post the results.

TTOP350

iTrader: (8)

Sounds booster related.

thejimsterz28

Ok I unhooked the booster and plugged it off with my thumb with no joy. I will still replace the booster, but I'm going to check very carefully the engine for any other vacuum leaks. The hoses were changed about 2 years ago so hopefully one is just loose or something. I'll spray gaskets too eith carb cleaner and see if I get lucky finding a leak.