vacuum leak problem
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The hose on the passenger side valve cover is part of the PCV system. It brings filtered air from the throttle body into the crankcase. The PCV valve on the driver's side sucks the air out of the crankcase and into the intake manifold.
They changed these connections from year to year. My car has aluminum tubes on both sides. Later years used rubber hose directly. The aluminum tube on the driver's side has a T and one side goes to the PCV valve and the other goes to the charcoal canister. Later years have the charcoal canister connected to the throttle body.
Later years have a third barb on the passenger side of the throttle body. I don't know when they started doing this. Mine has only the coolant hose and the PCV air source.
They changed these connections from year to year. My car has aluminum tubes on both sides. Later years used rubber hose directly. The aluminum tube on the driver's side has a T and one side goes to the PCV valve and the other goes to the charcoal canister. Later years have the charcoal canister connected to the throttle body.
Later years have a third barb on the passenger side of the throttle body. I don't know when they started doing this. Mine has only the coolant hose and the PCV air source.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The charcoal canister vacuum source on my car is teed off the PCV line. I know in later years they used the throttle body vacuum source for this.
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
this are the fact.
I remove the air filter and MAF.
block the throttle body oepneing compleately with my hand.
no air is coming into the engine true the front of the TB.
the engine keep running.
I pull out the hose on the passenger side valve cover.
block the hose with my finger
the engine stop. because i block the last sorce of air coming into the engine.
what is my problem
I remove the air filter and MAF.
block the throttle body oepneing compleately with my hand.
no air is coming into the engine true the front of the TB.
the engine keep running.
I pull out the hose on the passenger side valve cover.
block the hose with my finger
the engine stop. because i block the last sorce of air coming into the engine.
what is my problem
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
this are the fact.
I remove the air filter and MAF.
block the throttle body oepneing compleately with my hand.
no air is coming into the engine true the front of the TB.
the engine keep running.
I pull out the hose on the passenger side valve cover.
block the hose with my finger
the engine stop. because i block the last sorce of air coming into the engine.
what is my problem
I remove the air filter and MAF.
block the throttle body oepneing compleately with my hand.
no air is coming into the engine true the front of the TB.
the engine keep running.
I pull out the hose on the passenger side valve cover.
block the hose with my finger
the engine stop. because i block the last sorce of air coming into the engine.
what is my problem
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I mentioned before, I think your car is plumbed incorrectly. That hose should pull in air from in front of the throttle body, not behind it. My throttle body has 2 large ports on the passenger side. The lower one has vacuum and should be connected to the egr or plugged or whatever. I plug it in my car. The large port above it pulls in air from in front of the throttle body. Connect your breather hose to this line, plug the lower one and you will be good to go.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
this is the passenger side TB image. from top to bottom.
the first hose. go to the passenger side valve cover hole.
the secont hole. is seal.
the last hole there use to be for water. I delite that some time ago.
[IMG]
[/IMG]
the first hose. go to the passenger side valve cover hole.
the secont hole. is seal.
the last hole there use to be for water. I delite that some time ago.
[IMG]
[/IMG]
[/IMG]
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I don't have a picture, but I have another port in mine that does not pull vacuum. The small port underneath is plugged on mine too. Don't know what to tell you at this point except plug the big port and run a breather on top of your valve cover to let fresh air in. That's what it is supposed to pull in.
Instructor
Joined: Sep 2011
Posts: 107
Likes: 0
From: Colorado
First, do you have a Factory Service Manual? Without it yer pee'n in the wind.
Second, a code reader one that does live data display.
Thirdly, a real vacuum pump the kind used with the engine off.
Another vacuum testing tool is one that mounts on a propane bottle.
My vacuum leaks were under the dash and made the engine run like crap.
I guess the real question is what makes you think there a massive leak that effect performance?
Bill
Thread Starter
Drifting
Joined: Aug 2011
Posts: 1,861
Likes: 1
From: panama panama
I've been trying to follow what is happening and even went thru some of the 249 posts.
First, do you have a Factory Service Manual? Without it yer pee'n in the wind.
Second, a code reader one that does live data display.
Thirdly, a real vacuum pump the kind used with the engine off.
Another vacuum testing tool is one that mounts on a propane bottle.
My vacuum leaks were under the dash and made the engine run like crap.
I guess the real question is what makes you think there a massive leak that effect performance?
Bill
First, do you have a Factory Service Manual? Without it yer pee'n in the wind.
Second, a code reader one that does live data display.
Thirdly, a real vacuum pump the kind used with the engine off.
Another vacuum testing tool is one that mounts on a propane bottle.
My vacuum leaks were under the dash and made the engine run like crap.
I guess the real question is what makes you think there a massive leak that effect performance?
Bill
about the vacuum. just wanted to know. if I block the intake. does the rngine keep running?????
not sure about the vacuum leak any more. I am getting into the TPS now. since is not at spec.