Opti vent harness check - Chevy Impala SS Forum
Impala SS Forum
Go Back   Chevy Impala SS Forum > 91-96 Impala/B-body > Engine Problems/Maintenance
New User? Register - Forgot Password

Reply
 
Thread Tools Display Modes
  #1  
Old 04-16-2012, 08:23 PM
livinproof livinproof is offline
Junior Member
 
Join Date: Nov 2006
Location: k-zoo mich
Posts: 17
livinproof
Default Opti vent harness check

Im curious if there is a good way to check the opti vent harness more than just visually. My main concern being the one with the check valves. Check valve orientation is one way, allowing vaccum into the opti right or wrong?
Was going to replace put appear fine but figure id make sure everything flowing to right way. Gm replacement is pricy, but if i could make my own that would be cool. Just not fully understanding how the harness works.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 04-17-2012, 05:48 AM
4DoorSS's Avatar
4DoorSS 4DoorSS is offline
Senior Member
 
Join Date: Nov 2008
Location: Beautiful Chester County, PA
Posts: 4,658
4DoorSS is an unknown quantity at this point
Default

I know I saw a recent thread on this. Did you try a search on the Forum?
__________________
================================================== =============


'95 Caprice SS conversion - Bonny Buckets - 96 Column, Shifter and Console - 3.73 Gear and Herter tune - Z/28 Cluster - Blazer OH Console - Green/Pink bushings - Chromed Impala Wheels - Eibach Springs and Bilstein Shocks - Corvette Engine Dress - the list goes on and still more to do...it never ends.
Reply With Quote Quick reply to this message
  #3  
Old 04-17-2012, 10:12 AM
BALLSS BALLSS is offline
Senior Member
 
Join Date: Apr 2001
Location: Moorpark, CA
Posts: 5,802
BALLSS is on a distinguished road
Default

the "blue" part of the valve goes towards the intake
__________________
\'96 BBB 383/T-56
Reply With Quote Quick reply to this message
  #4  
Old 04-17-2012, 03:31 PM
livinproof livinproof is offline
Junior Member
 
Join Date: Nov 2006
Location: k-zoo mich
Posts: 17
livinproof
Default

ok looks like i had the larger (check valve) backwards.
Reply With Quote Quick reply to this message
  #5  
Old 04-17-2012, 05:42 PM
mtrhead79's Avatar
mtrhead79 mtrhead79 is offline
Senior Member
 
Join Date: Jul 2007
Location: phil. pa
Posts: 506
mtrhead79
Default

on mine the blue part is on the opti side
__________________
john
1994 caprice tri-y headers, raiss intake, flowmaster duals, edge 2800, 3:73 posi 9c1 rear lingenfelter cam, camaro mass air meter, trans go shift kit, pcm forless tune, 1.6 roller rockers, bee hive springs, deleted abs, frame is powder coated
Reply With Quote Quick reply to this message
  #6  
Old 04-17-2012, 06:44 PM
1slow96's Avatar
1slow96 1slow96 is offline
Senior Member
 
Join Date: Jun 2011
Location: Dayton , Ohio
Posts: 4,994
1slow96 is on a distinguished road
Default Opti vent harness check

The "blue" side of both valves faces the manifold (away from opti) I cannot overstate the importance of these valves pointing in the right direction. Verify proper ventilation. Either with a vacuum gauge (the best way) proper ventilation is indicated by the gauge slowly raising until manifold vacuum is reached,or with a piece of paper (common,but crude). Many cases of opti failure can be directly linked to ventilation,or lack thereof.
Reply With Quote Quick reply to this message
  #7  
Old 04-18-2012, 10:58 AM
BALLSS BALLSS is offline
Senior Member
 
Join Date: Apr 2001
Location: Moorpark, CA
Posts: 5,802
BALLSS is on a distinguished road
Default

Quote:
Originally Posted by 1slow96 View Post
Verify proper ventilation. Either with a vacuum gauge (the best way) proper ventilation is indicated by the gauge slowly raising until manifold vacuum is reached,or with a piece of paper (common,but crude). Many cases of opti failure can be directly linked to ventilation,or lack thereof.
are you saying Opti vacumn should read what the manifold vacumn is (18-19 in HG) at the blue nipple that goes into the rubber intake elbow?

Mine reads 4 at that point. It reads 18-19 on the hose that has the blue valves that plugs into bottom of Opti
__________________
\'96 BBB 383/T-56
Reply With Quote Quick reply to this message
  #8  
Old 04-18-2012, 12:43 PM
1slow96's Avatar
1slow96 1slow96 is offline
Senior Member
 
Join Date: Jun 2011
Location: Dayton , Ohio
Posts: 4,994
1slow96 is on a distinguished road
Default Opti vent harness check

Yes,or at least close to it. I've heard of cleaning the check valves with alcohol (not on the car) you may have a vacuum leak in the check valve,or more likely where the hose meets nipple. Check hose snugness at the opti itself. New lines aren't that expensive,get "fuel injection" line if possible. It holds up much better. At least cut 1/2" off each end of the existing lines,for more secure connections if you aren't prepared to swap out the lines.
Reply With Quote Quick reply to this message
  #9  
Old 04-18-2012, 01:16 PM
BALLSS BALLSS is offline
Senior Member
 
Join Date: Apr 2001
Location: Moorpark, CA
Posts: 5,802
BALLSS is on a distinguished road
Default

Quote:
Originally Posted by 1slow96 View Post
Yes,or at least close to it. I've heard of cleaning the check valves with alcohol (not on the car) you may have a vacuum leak in the check valve,or more likely where the hose meets nipple. Check hose snugness at the opti itself. New lines aren't that expensive,get "fuel injection" line if possible. It holds up much better. At least cut 1/2" off each end of the existing lines,for more secure connections if you aren't prepared to swap out the lines.
The blue nipple on vent hose does not have check valves. It runs straight to Opti. That line reads 4 in vac. The line with the check valves reads 18

This is a brand new vent harness, GM

The line that goes to the blue nipple fits the metal nipple on Opti and the line that goes to manifold has 2 check valves and goes to the larger "plastic" nipple on the Opti.

also this is a comment from Rocko about opti vent vacumn

"The disc looking thing in the opti harness is a vacuum limiter. designed to limit the vacuum to around 4inches i believe. It does need to be able to hold a small piece of paper. "
__________________
\'96 BBB 383/T-56

Last edited by BALLSS; 04-18-2012 at 01:22 PM.
Reply With Quote Quick reply to this message
  #10  
Old 04-18-2012, 02:02 PM
1slow96's Avatar
1slow96 1slow96 is offline
Senior Member
 
Join Date: Jun 2011
Location: Dayton , Ohio
Posts: 4,994
1slow96 is on a distinguished road
Default Opti vent harness check

All this is in the FSM. I want to help,but I'm weary of the endless debating about every little thing that this forum has become. If the vacuum was limited,then how could you have 18in. at the opti ,but the line with nothing on somehow reads 4in. If you've checked that line for a leak,then the only thing that occurs to me is that the opti itself is no longer sealed.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy Impala SS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:20 PM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
(c) 2007-2014 Impala SS Forum