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Running Rich?

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  #1  
Old 07-18-2010, 10:33 AM
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Default Running Rich?

So, I know my car is running very rich.
It smells like fuel, and the plugs are turning black.
Not to mention the carb is to big. It is for after I get my cam.
Holy 750 double pump.

What will the exhaust do?
"Black smoke, Blue Smoke, soot build up"

What will happen when the car is idling?
"smoke, loadup, try to choke"

I have duals that dump straight down, and the driveway has turned black from the soot. I cant tell if the car is smoking a little from burning oil. Or if it is just unburnt fuel. Doesnt smell like oil, smells like fuel and it burns your eyes. I cant see the smoke when I get on it, only when sitting at an idle. Doesn't smoke if I rev it up.

Wondering if maybe my valve guides dried out while the engine was sitting.

Probable just rich, but felt I should ask incase it was a sign of something else.
 
  #2  
Old 07-18-2010, 12:09 PM
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Is it running rich only at idle, or while cruising too? Has anybody followed behind you to see if their eyes burn? After it idles, your engine might be loading up and sound blubbery, and then sputter a little when you first goose it.
It might be rich because of the carb. But black dry sooty plugs could also mean you have weak ignition output, or your spark plug heat range is too cold.
Is your choke opening all the way?
Is your air cleaner clean?
Have you adjusted (weaned down) the two idle mixture screws (if it's a rich idle issue)?
Generally, you won't see smoke from the exhaust like when an engine is burning oil. But the rich smell and burning eyes is a dead giveaway for a rich mixture.
 
  #3  
Old 07-19-2010, 10:28 AM
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Is your choke opening all the way? yes twist tie holding it open all the time, I will double check that it hasnt loosened up.
Is your air cleaner clean? New, but it is one of those triangle edelbrock foam ones. nothing else fits under the hood.
Is it running rich only at idle, or while cruising too? Not sure, no one has followed be hind me. I can smell the fuel while driving, but not much. I cant see any smoke, but it am moving.

I think it is loading up at an idle. runs kinda ruff till I get on it. Wont idle for more then 5 minutes or 10 minutes. I know that carb is to big for my setup. But I will have a cam in a month or less. Im not buying a new carb for a month.

Have you adjusted (weaned down) the two idle mixture screws (if it's a rich idle issue)? I had them a lot lower trying to make it stop running so rich. I didn't notice the smoke as much, however the car choked off the line. I spent a night at the track trying to get the dead spot out (choke, bog, whatever). When you first got on it, the carb would choke and the car would sputter. After turning the idle mixture up I picked up 5 tense of a second and got the flat spot out.

So yes, I tried that and it helped but caused me to loose power. I hated having the car bog of the line.

I know the car is very rich, just didn't know if that would cause the soot and smoke. Smell is normal for a very rich car.

Do I need to do something about the ignition system. It is a stock HEI coil, MSD cap and rotor. Bosh Platnium plugs and Accel Wires.

Guess I can try turning the mixture down a little, see if I can find a happy spot.
Or just ignore it till I get the cam.
 
  #4  
Old 07-19-2010, 11:10 AM
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try smaller jets.
 
  #5  
Old 07-19-2010, 12:35 PM
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The bogging is usually caused by the accelerator pump stroke (too long or too short). It seems to me you are trying to relieve the bogging condition by making the idle overly rich. Try adjusting the idle mixture properly and increase the stroke on the accelerator pump.
 
  #6  
Old 07-19-2010, 12:36 PM
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the stroke on the accelerator pump? Say What?I have no idea what you are talking, about. I am going to Google it before asking anything.
 
  #7  
Old 07-19-2010, 12:53 PM
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Ok, So I read this article:
http://stockcarracing.automotive.com...ent/index.html

And it does seem like you may be correct.
I think I just need to move the set screw in the images below.


 
  #8  
Old 07-19-2010, 12:54 PM
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Look at the linkage arm, you'll see a plastic cam that the accelerator pump arm rides on. The cam can be mounted in two different positions to change the amount of accelerator pump squirt or the ramp speed. You can also buy different cams so you can experiment even more to change the settings. Let us know next year how that turns out!
It sounds like your carb is just over-jetted for your size engine.
 

Last edited by Camaro 69; 07-19-2010 at 12:57 PM.
  #9  
Old 07-19-2010, 12:59 PM
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So that orange cam has several holes in it. So I can just take that screw out and turn the orange cam.

Do you think that is the problem Camaro69, or should I just not worry about it till I get a larger cam.
And what do you mean by next year?
 

Last edited by gfrench; 07-19-2010 at 01:02 PM.
  #10  
Old 07-19-2010, 01:04 PM
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The cam setting can affect your off-line bog, but that is NOT your running rich problem. Things are going to change after the cam, so whatever you do now might need to get changed again. You can mess with it for fun now, if nothing else to see what kind of changes it does make.
 


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