Ironmike77

Hey guys having an issue with my 91 Camaro 5.0 TPI. Just recently got my lower intake manifold replaced with a new one. Because it was leaking coolant. Anyways now as I知 braking or slowing down my car idles up and down, eventually dying out sometimes on me. Thought maybe it痴 a brake booster issue? Hear a hissing sound as I press the brake pedal, saw videos where that could be a problem. Any help would be great.
https://youtube.com/shorts/dTmJridC2fc?feature=share https://youtube.com/shorts/9jx2rRqmpic?feature=share

aliceempire

iTrader: (14)

Vacuum leak most likely. You can fiddle around with brake cleaner and hope you find the leak or use a smoke machine (you can even make a diy one) to for sure find your leak. Mega common on tpi where there is 100 places to potentially leak. Good chance the gaskets on the lower were put on the wrong side.

Ironmike77

I really hope he didn稚 mix up the gaskets. I値l have to end up bringing it back to him. With brake cleaner, I just spray around the engine until I hear it bog down?

aliceempire

iTrader: (14)

IF the brake cleaner is sucked into the leak then you will hear a fairly clear change in engine speed. If the gaskets are on the wrong side then it won't be hard to find that in particular. But vacuum leaks can easily hide on tpi so it's hard to spray all the places and then you're hoping the leak is strong enough there to pull in the brake cleaner. I've even sprayed places that I knew leaked and didn't get a change in engine speed. I find it very ineffective. Kinda like playing the game Risk using darts partially blindfolded. A smoke machine will show you where your leak or leakS are.

Ironmike77

Can a bad brake booster cause these issues. Because when I press the brake pedal it causes a loud hissing. Also as I brake while driving, the pedal feels really soft than drops like 2 inches and finally becomes firm.

aliceempire

iTrader: (14)

A booster can leak vacuum, absolutely. Not too likely but very possible. Easy to test. Disconnect the vacuum line from the intake and cap it. Does the idle and running come back to normal? Note: DO NOT DRIVE while in the condition. While I assume you'd know that, one can never be sure.

Ironmike77

🤣🤣 of course! I値l definitely check that out though, thanks!