Notices
C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette

persistent spark plug fouling

 
Old 12-17-2018, 10:51 PM
  #41  
Bullshark
CF Senior Member
 
Bullshark's Avatar
 
Member Since: Nov 2003
Location: St. Charles Mo
Posts: 2,596
Likes: 0
Received 25 Likes on 22 Posts
CI 5 & 8 Veteran
Default

Take a look at the spark with the plug removed and grounded to block. Is it white and sharp snapping?
Bullshark is offline  
Old 12-17-2018, 11:00 PM
  #42  
Big2Bird
CF Senior Member
 
Big2Bird's Avatar
 
Member Since: Dec 2006
Location: Anaheim Ca.
Posts: 7,027
Received 447 Likes on 418 Posts
Default

Bad condenser you usually get an orange spark.

DUI units are HEI. They are really nice pieces:

http://performancedistributors.com/p...-distributors/

Last edited by Big2Bird; 12-17-2018 at 11:02 PM.
Big2Bird is offline  
Old 12-18-2018, 07:35 PM
  #43  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default

I think i have a lot to do this weekend. Ill be sure to tell everyone what i found out .....or ask more questions. Early when I had this problem i thought it might be the NEW distributor because the back cylinders where not firing. I thought it was the wire so I replaced them and checked with a spark plug light. The light went on so I figured it was working. But if what im hearing now the spark might no be strong enough? Ill look at the spark of the plug now.
Japery is offline  
Old 12-18-2018, 08:49 PM
  #44  
HeadsU.P.
CF Senior Member
 
HeadsU.P.'s Avatar
 
Member Since: Aug 2017
Location: Cool Northern Michigan
Posts: 2,165
Received 384 Likes on 363 Posts
Default

Is it just me or the camera angle? But in post #18 the end of the ground strap electrode is missing. It just looks short of reaching the center electrode. Maybe not.

Last edited by HeadsU.P.; 12-18-2018 at 08:50 PM.
HeadsU.P. is offline  
Old 12-18-2018, 09:57 PM
  #45  
Big2Bird
CF Senior Member
 
Big2Bird's Avatar
 
Member Since: Dec 2006
Location: Anaheim Ca.
Posts: 7,027
Received 447 Likes on 418 Posts
Default

Originally Posted by HeadsU.P. View Post
Is it just me or the camera angle? But in post #18 the end of the ground strap electrode is missing. It just looks short of reaching the center electrode. Maybe not.
Maybe. I "think" I see that as well.
Big2Bird is offline  
Old 12-19-2018, 10:19 AM
  #46  
HeadsU.P.
CF Senior Member
 
HeadsU.P.'s Avatar
 
Member Since: Aug 2017
Location: Cool Northern Michigan
Posts: 2,165
Received 384 Likes on 363 Posts
Default

Originally Posted by Big2Bird View Post
Maybe. I "think" I see that as well.
If the plug is perfectly fine, then we have had too much Egg-Nog.
HeadsU.P. is offline  
Old 12-19-2018, 10:20 AM
  #47  
pauldana
CF Senior Member
Support Corvetteforum!
 
pauldana's Avatar
 
Member Since: May 2003
Location: LA county ca
Posts: 9,907
Received 280 Likes on 225 Posts
Default

Originally Posted by HeadsU.P. View Post
If the plug is perfectly fine, then we have had too much Egg-Nog.

to much eggnog... it there,,,
pauldana is online now  
Old 12-19-2018, 10:30 AM
  #48  
Big2Bird
CF Senior Member
 
Big2Bird's Avatar
 
Member Since: Dec 2006
Location: Anaheim Ca.
Posts: 7,027
Received 447 Likes on 418 Posts
Default

Originally Posted by Japery View Post

these are the hotter plugs. Autolite AR3910
Can you post a better picture?
Big2Bird is offline  
Old 12-19-2018, 01:29 PM
  #49  
HeadsU.P.
CF Senior Member
 
HeadsU.P.'s Avatar
 
Member Since: Aug 2017
Location: Cool Northern Michigan
Posts: 2,165
Received 384 Likes on 363 Posts
Default

I'm thinking, two more shots of Egg Nog (spiked) and the picture will clear right up.

(moments later)

Nope. Still blurry.
HeadsU.P. is offline  
Old 12-19-2018, 06:35 PM
  #50  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default

I dont think the Edelbrock carb has a power valve but I could be wrong.
Japery is offline  
Old 12-19-2018, 07:09 PM
  #51  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default


Plenum looks clean

Last edited by Japery; 12-19-2018 at 07:12 PM.
Japery is offline  
Old 12-19-2018, 07:12 PM
  #52  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default


it looks grey because of the flash but its black powder.
Japery is offline  
Old 12-19-2018, 07:20 PM
  #53  
HeadsU.P.
CF Senior Member
 
HeadsU.P.'s Avatar
 
Member Since: Aug 2017
Location: Cool Northern Michigan
Posts: 2,165
Received 384 Likes on 363 Posts
Default

Yes, intake does look clean. But I still question the grd strap electrode on that plug. Looks short to me.

Blue Print puts the ALT on the passenger side? H-m-m-m-m. More work for you eh?

Anyway, that plug should still fire, just not normal. If you were expecting fuel to be sitting in the plenum, it evaporates pretty fast. I bet its flooding some how.
Hard to tell but looks like the drivers side of your carb base gasket is stained with fuel, leakage? Maybe?

So. Lets digress:
You have a Eddy intake designed for a Spreadbore carb.
You have an Eddy carb
You have an Squarebore bolt pattern.
You have a 4 Hole gasket or spacer.
You are experiencing a flooding condition.

There must be a clue there somewhere. Not sure you should be using the four hole gasket. Maybe an open style would be better What I am getting at, I wonder if that gasket is blocking any ports on your Eddy carb?

Last edited by HeadsU.P.; 12-19-2018 at 07:36 PM.
HeadsU.P. is offline  
Old 12-19-2018, 08:11 PM
  #54  
zwede
CF Senior Member
 
zwede's Avatar
 
Member Since: Sep 1999
Location: Plano TX
Posts: 11,124
Received 204 Likes on 182 Posts
Default

Originally Posted by HeadsU.P. View Post
But I still question the grd strap electrode on that plug. Looks short to me.
It's a cut back ground strap. Old racer's trick from back in the day. I guess this Autolite comes like that? Anyway, cutting the strap back like that it will still fire, just won't last very long. it also won't make more power that way, go with a regular ground strap.
zwede is offline  
Old 12-19-2018, 09:33 PM
  #55  
pauldana
CF Senior Member
Support Corvetteforum!
 
pauldana's Avatar
 
Member Since: May 2003
Location: LA county ca
Posts: 9,907
Received 280 Likes on 225 Posts
Default

I agree... looks clean..

back to the carb...
pauldana is online now  
Old 12-19-2018, 10:25 PM
  #56  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default

A thought. The ignition that im using(dui from high performance) says i can widen the gap to 50,so i figured have the half strap at 45. thoughts? On that note i checked the ohms on the ignition parts and they're all good. The carb is my next move i guess. Check the float and the pressure gauge. Can you think of anything else?
Japery is offline  
Old 12-19-2018, 10:28 PM
  #57  
Japery
CF Member
Thread Starter
 
Member Since: Jan 2015
Location: Rochester NY
Posts: 84
Received 0 Likes on 0 Posts
Default

Maybe this is a dumb question but do you get a gasket to fit the carb or the manifold?
Japery is offline  
Old 12-20-2018, 08:57 AM
  #58  
Rescue Rogers
CF Senior Member
Support Corvetteforum!
 
Rescue Rogers's Avatar
 
Member Since: Oct 2015
Location: YUPPY HELL Westford MASS
Posts: 5,226
Received 774 Likes on 695 Posts
2016 C3 of Year Finalist
Default

there should be a metal adapter plate for the spreadbore to squarebore carb. Edelbrock make it and says its mandatory. Its about 1/8" thick and needs gaskets above and below.
Rescue Rogers is offline  
Old 12-20-2018, 12:24 PM
  #59  
Jebbysan
CF Senior Member
 
Jebbysan's Avatar
 
Member Since: Mar 2012
Location: New Braunfels Texas
Posts: 3,217
Received 385 Likes on 340 Posts
Default

Edelbrock wants 6 or below psi. Any more than that blows the needle and overflows the bowls which comes out through the booster on the primary.....flooding the engine.
Put a regulator on it....dial it for 5.5 psi and report your results......

Jebby
Jebbysan is offline  
Old 12-20-2018, 12:37 PM
  #60  
v2racing
CF Senior Member
 
v2racing's Avatar
 
Member Since: Mar 2008
Location: Spring Park MN
Posts: 2,643
Received 264 Likes on 220 Posts
Default

Originally Posted by Japery View Post

it looks grey because of the flash but its black powder.
I always cut back my straps on the Top Fuel stuff. The shorter ground strap exposes the spark for better ignition of the hard to light off nitromethane. The ground straps also would stay cooler being shorter and wouldn't burn off as bad. I never saw much improvement in gas engines though, although I have run them like this on the street and they last just as long as regular plugs with long ground straps.

Mike
v2racing is offline  

Thread Tools
Search this Thread
Quick Reply: persistent spark plug fouling


Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: