Finding vacuume leak
Supreme Member
Joined: Sep 1999
Posts: 3,197
Likes: 10
From: Manassas VA
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
Since i always have some around, i've always used carb cleaner. Just listen for the idle speed to pick up ahair as you spray it with the tube around anything that could leak, including on hoses themselves. After years of heat they can crack and not even be visible.
...ed
...ed
Senior Member

Joined: Nov 2000
Posts: 762
Likes: 2
From: Riverside, CA
Car: 1987 Camaro IROC-Z
Engine: 305TPI
Transmission: 700R4
my opinion?
just change all of the tubing, it will take you an afternoon to do it right, heating up the hoses one by one and bending them into the correct shape, but it's worth it and you will thank yourself in the end for doinig the job right..
i changed all of the hoses on all of my cars and they all run nice...
vacuum leaks are usually felt at idle, go away when revving, and tend to get worse as the engine gets hotter.. that's a joe-blow explanation but might give you some idea..
------------------
Webmaster: www.IROC-Z.org
just change all of the tubing, it will take you an afternoon to do it right, heating up the hoses one by one and bending them into the correct shape, but it's worth it and you will thank yourself in the end for doinig the job right..
i changed all of the hoses on all of my cars and they all run nice...
vacuum leaks are usually felt at idle, go away when revving, and tend to get worse as the engine gets hotter.. that's a joe-blow explanation but might give you some idea..
------------------
Webmaster: www.IROC-Z.org
carb cleaner works great for finding a vaccuum leak. you just try to find an area where you think it's acurring, and spray it ont hat area. If the carb cleaner is sucked in, you have a leak, simple as that.
Senior Member
Joined: Oct 1999
Posts: 735
Likes: 2
From: Portales, NM USA
Car: 86 T/A
Engine: 5.0 TPI
Transmission: 700R4
Carb spray is great for determining you HAVE a vacuum leak, however under certain circumstances it can be worthless for pin pointing the leak.
If you spray it in the area of the cold start valve and your engine revs.... what is it?
Cold Start Valve
Fuel Injector
Runner to Manifold
Manifold to Block
EGR
Brake Booster
... or any of the vacuum hoses in a near proximity. I sprayed carb cleaner for months replacing parts only to find my intake was loose and cold start flange was bent.... both of which would have given me the dreaded code 44.
If you spray it in the area of the cold start valve and your engine revs.... what is it?
Cold Start Valve
Fuel Injector
Runner to Manifold
Manifold to Block
EGR
Brake Booster
... or any of the vacuum hoses in a near proximity. I sprayed carb cleaner for months replacing parts only to find my intake was loose and cold start flange was bent.... both of which would have given me the dreaded code 44.
Thread
Thread Starter
Forum
Replies
Last Post




