Fouling issues

[Slink]

Hey guys,
Would anyone be able to point me in the right direction to read on issues of fouling? I don’t want to bother you guys on the issue would like to research more. Basics is I have rebuilt 305, new distributor, wires, plugs, and edelbrock carb. I can drive 40mph or less for about a week then fouling occurs. If I get on highway it’s one trip and fouling. I have been told to go back to original carb (quadrajet). Gotta research more and decide what to do from here.

 

[Goldie Driver]

Not sure what you are after on this one , so this may or may not help.

Spark-plug-trouble-tracer.pdf (championpowersports.eu)

Pretty pictures, too. LOL

You must be registered for see images attach

 

[82sbshortbed]

Gap plugs to.045 and get rid of the edelbrock carb and go back to the quadrajet. That fixed my plug fouling and rich running.

 

[Slink]

Gap plugs to.045 and get rid of the edelbrock carb and go back to the quadrajet. That fixed my plug fouling and rich running.

All plugs are at .045 now, so guess quadrajet will be next. Getting it rebuilt now. Thank you, I was really hoping the Edlebrock carb would be good to go. As a side note has anyone having this kind of issue ever had it foul the front plugs first, starting at plug one?


Sent from my iPhone using Tapatalk

 

[C10MixMaster]

I think a pick of the fouling would help make a more accurate diagnosis. It could be fuel fouling or oil fouling and that's two different directions to go in. If it is fuel fouling you can rejet your eddy although a qjet is a better carb.

 

[Slink]

You must be registered for see images attach

Sorry it’s the only one on my phone at the moment. The foul like this each time and is a dry soot not wet like oil or something.


Sent from my iPhone using Tapatalk

 

[C10MixMaster]

You must be registered for see images attach

Sorry it’s the only one on my phone at the moment. The foul like this each time and is a dry soot not wet like oil or something.


Sent from my iPhone using Tapatalk

not the best pic but that's a lot of fouling im leaning towards oil. that much fuel fouling should run like crap. possible rings not seated, leaky intake, leaky valve seals pcv bad (i bought a zz4 motor that had plugs like that and all it was, was a bad pcv valve).

 

[gotyourgoat]

You must be registered for see images attach

Sorry it’s the only one on my phone at the moment. The foul like this each time and is a dry soot not wet like oil or something.


Sent from my iPhone using Tapatalk

This doesn’t look fouled at all. A little soot maybe.
My fouled is digging and scraping the carbon out with a pick and a little screw driver.

https://www.gmsquarebody.com/threads/spark-plug-pictures-diagnostic-thread.30446/

 

[Slink]

Thanks for the lead, I see what you mean.


Sent from my iPhone using Tapatalk

 

[Bextreme04]

Thanks for the lead, I see what you mean.


Sent from my iPhone using Tapatalk

How many miles on the rebuild? Any other drivability concerns? Did you adjust the carb for the engine or just slap it on? Have you done an idle mixture adjustment?

 

[Bextreme04]

Also, what fuel pump are you running? Have you checked the fuel pressure? The edelbrock carbs are notorious for fuel blowing past the float needle with fuel pressure above about 5psi. Since the factory GM mechanical fuel pumps run around 7psi... this is usually a problem.

 

[Knight84]

How many miles on the rebuild? Any other drivability concerns? Did you adjust the carb for the engine or just slap it on? Have you done an idle mixture adjustment?

Just looks like it's running rich. Maybe tune the carb before throwing it all away and starting over? The edlebrock's look fairly simple to adjust. In most scenarios it's the simple answer.

 

[Bextreme04]

Just looks like it's running rich. Maybe tune the carb before throwing it all away and starting over? The edlebrock's look fairly simple to adjust. In most scenarios it's the simple answer.

I think you quoted the wrong guy on accident... not my truck. I agree though... while the quadrajet is a better carb he already has a new edelbrock and its going to be better to figure out what is going on with his current setup. I would bet it is jetted too big for a stock rebuilt 305 and also it didnt get the idle mixture adjusted properly

 

[Knight84]

I think you quoted the wrong guy on accident... not my truck. I agree though... while the quadrajet is a better carb he already has a new edelbrock and its going to be better to figure out what is going on with his current setup. I would bet it is jetted too big for a stock rebuilt 305 and also it didnt get the idle mixture adjusted properly

I was attempting to piggyback on your comment to adjust instead of just slapping it on. An @ probably would have worked better as an agreement with your statement.

 

[Bextreme04]

I was attempting to piggyback on your comment to adjust instead of just slapping it on. An @ probably would have worked better as an agreement with your statement.