Another EGR question. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-21-2006, 05:01 PM
Member
 
Last photo:
Join Date: Feb 2004
Location: N Ga.
Posts: 272
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Another EGR question.

This ?, has not been answered in previous posts.
I gotta '85 Pontiac,with 305, It's gotta pass emission test. Took it to get tested, and failed, NOx is high. Indicates an EGR problem, or possibly catalytic converter.
EGR valve is working, clean, and free.
When the car is at idle, and the EGR is opened it should make the engine run rough or even quit. Mine won't. Open EGR and no change.
First thought is Heat rizer in th' intake is stopped up. So I remove th' intake,(hadda coolant leak anyway). Heat rizer is clean and clear.
Getting good vacuum signal to EGR, but when opened at idle, there is no change. WHY?!

At least I got th' coolant leak fixed

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-21-2006, 08:47 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,654
Wiki Edits: 0

Thanks: 15
Thanked 58 Times in 55 Posts
Did you check the heat riser in the head itself? carbon can build up into a clot in the head passage also. Have you carefully checked the valve to assure the valve itself is opening? I`ve seen one broken unit where the assembly moved but the valve didn`t since it was broken off. Have you checked the passage that goes into the intakes plenum? Just because it gets to the valve doesn`t mean it`s getting to the plenum.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-22-2006, 05:21 AM
Member
 
Last photo:
Join Date: Feb 2004
Location: N Ga.
Posts: 272
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by DoubleVision
Did you check the heat riser in the head itself? carbon can build up into a clot in the head passage also. Have you carefully checked the valve to assure the valve itself is opening? I`ve seen one broken unit where the assembly moved but the valve didn`t since it was broken off. Have you checked the passage that goes into the intakes plenum? Just because it gets to the valve doesn`t mean it`s getting to the plenum.
checked all that. the head is clear, the intake manifold is open and free of debris, the valve is working fine. when open you can blow through it and when closed you cannot. I'm stumped. That's why I posted this question.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-22-2006, 07:09 PM
cboy's Avatar
Member
 

Last journal entry: Finished
Last photo:
Join Date: Jan 2004
Location: Atwater, CA
Age: 69
Posts: 3,918
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
You mentioned in your original post that it also might by your cat. Why did you eliminate the coverter and concentrate only on your EGR?
__________________
Always learning...and sharing what I've learned. The Scratch-Built Hot Rod.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-22-2006, 11:37 PM
curtis73's Avatar
Hates: Liver. Loves: Diesel
 
Last wiki edit: How to find cheap parts
Last journal entry: 1999-2001: Getting it on the road
Last photo:
Join Date: Dec 2005
Location: Pittsburgh, PA
Age: 40
Posts: 5,128
Wiki Edits: 16

Thanks: 0
Thanked 2 Times in 2 Posts
I think he probably deduced that since the EGR isn't causing a rough idle that it might be the problem.

What I would do... poor man's experiment Take the cats off, or at least loosen them enough that there is a serious leak. Then see if the EGR test causes a rough idle. I can't see why a clogged cat would mask EGR failure but you never know.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-23-2006, 04:33 PM
kain13's Avatar
Registered User
 
Last photo:
Join Date: Apr 2006
Location: lubbock,Tx
Age: 38
Posts: 120
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i did emissions for six years in las Vegas Nevada.
was the car at operating temp how long did you drive it before the test,does it take 92 octane fuel and you put 87 in it?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-23-2006, 05:31 PM
Member
 
Last photo:
Join Date: Feb 2004
Location: N Ga.
Posts: 272
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by kain13
i did emissions for six years in las Vegas Nevada.
was the car at operating temp how long did you drive it before the test,does it take 92 octane fuel and you put 87 in it?
Vehicle was up to full operating temp, about a 30 min. drive, the eng. is a low comp 305, High octane is not necessary, However, for the 2nd test, I hadda git gas, so I put in about 5 gal. of premium. (Dam! That stuff cost as much as 100LL, so much for th' STC ). I elected to abort th' test, when apparent that failure was emminent. (that saved my free re-test )

Remember, we're talkin about an '85 Pontiac Parisienne, (ghetto boat).
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-23-2006, 05:36 PM
Member
 
Last photo:
Join Date: Feb 2004
Location: N Ga.
Posts: 272
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by cboy
You mentioned in your original post that it also might by your cat. Why did you eliminate the coverter and concentrate only on your EGR?
DEDuced Reconing, Bein's how th' opening of th' EGR did not induce rough idle, I decided that I would check there first. ( cheaper too! )

I'm gonna install a new Cat Converter, an' iffin' it don't pass, it's gonna git a brand new ZZ572/720 crate motor!! (I kinda hope it don't pass)

Last edited by st3gamefarm; 05-23-2006 at 05:44 PM.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-23-2006, 05:56 PM
Registered User
 
Join Date: May 2006
Location: virginia
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Egr

hi,check this.Remove the egr valve.Have a helper start the engine,then you be under the hood.Put your thumbs over both ports of the egr passages.One should have exhaust pressure and the other should have vacum,if no vacum is present you are stopped up in the intake manifold.Simple!Good luck
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
383 stroker 73monte Engine 11 05-07-2014 08:08 AM
supercharger.... 73monte Engine 16 07-24-2010 10:27 AM
Ignotion Set-ups Native Gearhead Engine 8 11-29-2003 01:20 PM
Hi All I just Joined, Questions Re:454 rebuild Gay-Shark Engine 8 11-29-2003 10:25 AM
EGR valve not working lamothe1 Engine 15 04-30-2003 02:59 PM


All times are GMT -6. The time now is 03:00 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.