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Discussion Starter #1 (Edited)
Hey Guys,

I am having a big problem with the Edelbrock carb I put on my 1967 Camaro with a 350.

The carb is a Edelbrock 1406 Performer Series. I believe it is 600 cfm. I live in Colorado at 5800' Elevation so I put 1456 rods and 1424 rods in it.

Ever since I have put this carburetor on the passenger side band is running pig rich, at idle it is putting out clouds of smoke and while driving is even worse. The car starts up fine and doesn't choke out at all. It also doesn't seem to respond very well at all when I turn the adjustments up front all the way in. I was thinking that I possibly had to much fuel pressure so I bought a regulator and a gauge since it has a external electric fuel pump and I am only showing 2-3 psi fp at idle.

If anyone has any idea's it would help because I have been pulling my hair out for a few months with this and I am obviously stupid when it comes to carbs :yes:

Here is a pic of how everything is hooked up to the carb just in case I did something wrong,



Thanks!

John
 

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What's your vacuum reading at an idle?.....Did you happen to change the metering rod springs when you changed the metering rods?.....I believe the stock springs are orange (5"Hg) but I'd have to look that up.....It sort of appears that something is going on with the idle circuit!


Also, did you try running your vacuum advance to the "full" vacuum port on the other side?
 

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http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf

I assume you mean 1424 jets. .073 on the lean step with a .089 jet... that's pretty lean. but you are at 5800ft. the manual i linked to above gives some guidelines for high altitude operation.

What exactly are the problems you're having? does the car run and drive okay, you just have the smoke problem? tell us more about the driveability.

what color smoke? black smoke indicates excessively rich. if it's white or blue smoke the problem isn't the carb, you've got a coolant/oil leak on the right bank. turning in the idle screws all the way cuts off the fuel to the idle circuit and will stall the car when at idle.
 

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and when you say "adjustments up front" i'm assuming you mean the idle mixture screws.

one other thing i noticed is that your vacuum advance is hooked up to ported vacuum. i'd switch it to full manifold vacuum (the port you have capped off) and cap off the ported vacuum. a very good writeup was done in another thread about ported vs. full manifold vacuum advance. do a search on the topic, you'll find it.
 

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Discussion Starter #5
What's your vacuum reading at an idle?.....Did you happen to change the metering rod springs when you changed the metering rods?.....I believe the stock springs are orange (5"Hg) but I'd have to look that up.....It sort of appears that something is going on with the idle circuit!


Also, did you try running your vacuum advance to the "full" vacuum port on the other side?
I didn't change the springs, they are the same that were with the carb when it came out of the box.

As far as checking the vacuum reading I haven't yet so I would have to figure out how to do that. I did go ahead and run the vacuum advance to the full port and it seems to react better but still seems rich.
 

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Discussion Starter #6
http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf

I assume you mean 1424 jets. .073 on the lean step with a .089 jet... that's pretty lean. but you are at 5800ft. the manual i linked to above gives some guidelines for high altitude operation.

What exactly are the problems you're having? does the car run and drive okay, you just have the smoke problem? tell us more about the driveability.

what color smoke? black smoke indicates excessively rich. if it's white or blue smoke the problem isn't the carb, you've got a coolant/oil leak on the right bank. turning in the idle screws all the way cuts off the fuel to the idle circuit and will stall the car when at idle.
Aaron,

I was referencing the part numbers I had from my ticket when I bought them. Just after I wrote this I was paying more attention to the color of the smoke and it appears to be mostly white smoke and with any "blip" of the throttle it is a ton, I am guessing that is coolant? I was thinking of trying a compression test in all cylinders on that bank to see what it reads, what is expected for a 350?

While driving I was getting a lot of sputtering and popping out of the exhaust.

Thanks,

John
 

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I'm afraid to say that this is not a carburetor related problem as it would throw out black smoke out the exhaust!.....Pull your spark plugs out and check them for wetness!....Sorry to hear about this!
 

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Discussion Starter #8
I'm afraid to say that this is not a carburetor related problem as it would throw out black smoke out the exhaust!.....Pull your spark plugs out and check them for wetness!....Sorry to hear about this!
I sure will, Like I said I am going to go ahead and do a compression test here in a few minutes. It will def be interesting! We will see what this test says. :beers:

Thanks!

John
 

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I run the 1405 carb. which is the same except it was a manual choke. It is on a 327 and I had to lean it down. I can't remember which rods and jets that I have. I do run full vacuum - NOT ported. The mixture screws were set to achieve the most manifold vacuum. It still ran excessively rich and my clothes reeked of fuel. I got mad one day and turned each mixture screw in - one full turn from where it was. This should have made it excessively lean, but I was beyond caring at this point. Car now runs great and no more smell ! Your 2-3 lbs of fuel pressure sounds pretty low. I would try 5. I also had to lean down the secondary jets.
 

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Compression looks fine for a low compression engine ! The biggest variance between the lowest cylinder and the highest is only about 8 %. Average compression of 129.4 PSI. Not even a 4 % variance from the average.
 

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I am guessing 170 PSI would be normal for about a 8.5 to 9 : 1 compression engine. My 327 is 200 PSI and it is about 9.5 - 9.7 compression ratio. A lot depends on the amount of overlap your camshaft has, as it will "bleed off" compression.
 

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Discussion Starter #14
I am guessing 170 PSI would be normal for about a 8.5 to 9 : 1 compression engine. My 327 is 200 PSI and it is about 9.5 - 9.7 compression ratio. A lot depends on the amount of overlap your camshaft has, as it will "bleed off" compression.
Yeah that's what I was thinking. I know the cam is a 292 and I don't know much more about it. I am still puzzled on the smoke pouring out but I guess it's time to tear it out and have it re-worked?
 

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Not necessarily. In the 80's we were very happy to get 120 PSI. If your heads have 76cc chambers, you will never get any higher compression. Your numbers look ok for that ! :)

I would change to full manifold vacuum for your distributor and retune ! Then see where you are at !
 

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Hmm... I'm guessing a 350 with some miles on the rings, big chamber heads, stock eyebrow pistons and stock deck height/gasket and a fairly large cam for your cr (just guessing the cr is 8.50-9:1?) 120 wouldn't be anything to worry about.

I think you will benefit more from a spring change on top of the metering rods. You prob have 10"hg at best with that cam and the stock orange springs are in the load phase (when you romp on it and the vacuum goes way down) I'm guessing your carb is on the wrong circuit.

When I installed a large cam in a 327 with a 1407 edel I got 8"-15" hg and PIG rich at idle, and 9 out of the 10 people I have talked with say I need to change the springs, a neighbor had a similar prob, changed his springs and solved it for him.

Give the car a good WOT run if you can then shut it off and pull the plugs.
Also when I switched the vac. advance from ported to full manifold I had to re time and reset the idle, make sure you do this. When I did and I put the pedal to the floor it would just spin without messing with the clutch when it was on ported so there is more power found in full vacuum, in my case at least.

Also add, I think I have the same fuel psi gauge (autozone special) Don't even bother looking at it, they are nowhere near accurate, mine would flick violently and eventually read 2-3psi at idle.

I apologize for the long post, thinking out loud.
 

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Discussion Starter #17
Hmm... I'm guessing a 350 with some miles on the rings, big chamber heads, stock eyebrow pistons and stock deck height/gasket and a fairly large cam for your cr (just guessing the cr is 8.50-9:1?) 120 wouldn't be anything to worry about.

I think you will benefit more from a spring change on top of the metering rods. You prob have 10"hg at best with that cam and the stock orange springs are in the load phase (when you romp on it and the vacuum goes way down) I'm guessing your carb is on the wrong circuit.

When I installed a large cam in a 327 with a 1407 edel I got 8"-15" hg and PIG rich at idle, and 9 out of the 10 people I have talked with say I need to change the springs, a neighbor had a similar prob, changed his springs and solved it for him.

Give the car a good WOT run if you can then shut it off and pull the plugs.
Also when I switched the vac. advance from ported to full manifold I had to re time and reset the idle, make sure you do this. When I did and I put the pedal to the floor it would just spin without messing with the clutch when it was on ported so there is more power found in full vacuum, in my case at least.

Also add, I think I have the same fuel psi gauge (autozone special) Don't even bother looking at it, they are nowhere near accurate, mine would flick violently and eventually read 2-3psi at idle.

I apologize for the long post, thinking out loud.
Ha the good ole autozone special! Cheers to that damn pos :beers:.
I will have to re-time and mess with the a/f adjustments a little bit tomorrow. I just have to get more familiar with how to properly time this motor and how much timing to run it at.... I am not so familiar with distributors and carbs anymore. It seems to be smoking less now until it warms up but if I even blip the throttle it pours a smoke screen.
 

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Hey John, I tried to run an Edelbrock 750 on my current set up and could never get it to run right up here in the thin air of Colorado. I bought a Holley 700 double pumper and put in the jets for 6,000 feet and it runs like a beast now. I hear of lots of guys running the Edelbrock carbs with minimal issues, but I found the opposite.
 

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I'd fix the smoking issue before going any further. Sounds like one side intake gasket didn't seal up. Your wasting your time trying to tune around it.
 

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Check the float on the passenger side. Edelbrocks have a float on each side of the carb. Pull the 8 screws that hold the top on and check the float level. The easiest way to set an Edelbrock float is to use a 5/16" drill bit and lay it between the float edge and the airhorn gasket. You are looking for slight movement in the float when you slide the drill bit back and forth under the float.
 
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