1973 engine vacuum question ... PCV delete ?
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,271
Likes: 1
From: PA
1973 engine vacuum question ... PCV delete ?
New to vettes and still learning about the vacuum system they have. I have been chasing an engine vacuum leak for a few weeks and want to trouble shoot the PCV system and whatever it's hooked to.
I want to temporarily bypass the PCV connection to the carb and all vacuum related components.
What components share that system ? I know the line goes to the vapor canister......anything else hooked into that system on a stock set up ?
I want to temporarily bypass the PCV connection to the carb and all vacuum related components.
What components share that system ? I know the line goes to the vapor canister......anything else hooked into that system on a stock set up ?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Well, the PCV valve is not hooked up to any vacuum lines. There is a hose running from the vapor canister to the PCV valve and then on to the base of the carb. But that is to draw fuel vapors into the carb and burn them with the fuel charge from the carb. It really has no impact on manifold vacuum. There is another line from the carb going to that vapor canister which [I believe] is 'ported' vacuum. That allows the canister to send those vapors to the PCV valve/carb only when the throttle was not at an idle condition.
If you are chasing down a vacuum related problem, just eliminating useful systems is not the method to use. You need a vacuum gauge, some rubber hose lines, a "T" fitting or two, and some needle nosed pliers and/or small vise-grips or clamps. There are specific (and simple) strategies to chase down and correct vacuum leaks. There are many archived threads on this issue that you can use the SEARCH function to review. Or, you can buy an inexpensive manual on the vacuum circuits of various C3 years and how do diagnose problems with them. Most of the Corvette parts places have them.
If you are chasing down a vacuum related problem, just eliminating useful systems is not the method to use. You need a vacuum gauge, some rubber hose lines, a "T" fitting or two, and some needle nosed pliers and/or small vise-grips or clamps. There are specific (and simple) strategies to chase down and correct vacuum leaks. There are many archived threads on this issue that you can use the SEARCH function to review. Or, you can buy an inexpensive manual on the vacuum circuits of various C3 years and how do diagnose problems with them. Most of the Corvette parts places have them.
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,271
Likes: 1
From: PA
I guess it would have impact on manifold vacuum if the canister was bad ? I got gauges and hoses for sure. Thanks for the reality check on trouble shooting......I guess I was just hoping for someone to do the work for me. Maybe link a thread or share a similar experience. I'm not planning on deleting these systems for good....just for diagnosis.
