C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

egr help

Thread Tools
 
Search this Thread
 
Old Jul 27, 2014 | 01:21 PM
  #1  
ray1979's Avatar
ray1979
Thread Starter
Instructor
15 Year Member
 
Joined: Sep 2006
Posts: 185
Likes: 2
From: Easton PA
Default egr help

Quick backround. 88 corvette auto 24k miles I was having a issue of knock counts and spark retard on part to full throttle. Check the knock circuit all looks good. Today I when to check the egr valve and egr solenoid. I applied vacuum to the egr valve and it held vacuum I also heard it moving. Then I checked the solenoid as per the manual. then I tested the vacuum on the solenoid. The service manual states that the solenoid fails however when I apply vacuum it holds then releases as I think it should. Now here is the part I need help with. I then go to start the car and it would hardly start. Once running the idle was bad I give it gas and it smooths out. then back to a bad idle.
before this the car ran and idled very well. Not sure if applying vacuum to the egr stirred things up. It is not setting any codes

Last edited by ray1979; Jul 27, 2014 at 01:39 PM.
Reply
Old Jul 27, 2014 | 02:40 PM
  #2  
MrWillys's Avatar
MrWillys
Drifting
 
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
Default

Sounds like a vacuum leak?
Reply
Old Jul 27, 2014 | 03:00 PM
  #3  
ray1979's Avatar
ray1979
Thread Starter
Instructor
15 Year Member
 
Joined: Sep 2006
Posts: 185
Likes: 2
From: Easton PA
Default

Possibly but all the vacuum lines are good. And the egr holds vacuum. Unless the solenoid is letting vacuum through. I will try capping off
Reply
Old Jul 27, 2014 | 04:09 PM
  #4  
cudamax's Avatar
cudamax
Burning Brakes
 
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
Default

Is the EGR opening While its Idling like crap pull the vacuum and push it in to try and seat it. As a Diagnostic tool only Get a empty tin can bottom or a coffee can bottom and remove the EGR and make up a plate to fit on the bottom of the EGR and block it Sometimes the nipple of the EGR has to go
Reply
Old Jul 27, 2014 | 04:36 PM
  #5  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default

Don't guess at quality of manifold vac, put a gauge on it to see what is the actual value.
Reply
Old Jul 27, 2014 | 08:40 PM
  #6  
ray1979's Avatar
ray1979
Thread Starter
Instructor
15 Year Member
 
Joined: Sep 2006
Posts: 185
Likes: 2
From: Easton PA
Default

Did some more testing the solenoid passes the test found out when I applied vacuum to the egr it was stuck fully open. I blew into the valve and it seated fully. It will release on its own as long as it not fully open. maybe it is carboned up. once seated the car idled perfectly I will remove it for cleaning. I might just replace it as the acdelco part is only $52.00. the part number on the valve is 17086078 I looked it up and it shows 88 corvette can anyone confirm that as the original part?

Last edited by ray1979; Jul 27, 2014 at 09:23 PM.
Reply
Old Jul 27, 2014 | 09:12 PM
  #7  
cudamax's Avatar
cudamax
Burning Brakes
 
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
Default

UR Welcome and u can take those off pull the sol and soak em
Reply

Get notified of new replies

To egr help





All times are GMT -4. The time now is 05:45 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE