Edelbrock 1406 failed emissions

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VAL

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Well, took my truck to emissions, they said something was wrong with the eddy 1406
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carb. Can anybody tell me exactly what all these numbers mean? And possible push me in the right direction for a fix. I spoke with some friends and they recommended a rebuild kit. I just need a second opinion.
 

Georgeb

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Looking at your sheet it appears that you are running rich during the loaded test thus the high CO reading. Please provide us with some more information:
Do you have a catalytic converter?
What are you running for an ignition system?
What is your base ignition timing set at?
What port is your vacuum advance connected to ported or manifold?
Have you done any tuning on the carburator like rods, jets or springs?

With this info collectively we can all chime in to help.
 

74 Shortbed

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The 1406 is calibrated for economy but the 1400 is even leaner, might want to change the rods and springs.
 

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It's a real crap shoot trying to tune for emissions without the proper equipment. George is right, you're running rich under load. You need to lean it out, but as you do so the hc readings will climb. You have some room to work with there but whether or not the co can come down below 1.20 without exceeding 220 on the hc side is anyone's guess. That's why being able to see the readings as you tune is necessary. In Cali, they didn't used to charge for a retest and guys were going out in the parking lot, tweaking the carb a bit, and getting retested to see what difference it made. I remember this one guy, I tested his VW bug over thirty times in one day. It finally passed, but the state got wise to that crap and started charging $7 for a retest so it was cheaper to go pay a mechanic. I don't know how AZ. does it, but in Cali if you went to a state certified "Blue Shield" mechanic and he certified he had tuned the vehicle to the best of his ability, you would get a certificate allowing registration even if the vehicle didn't pass emissions. It was sort of a good faith waiver. If people did it themselves or went to an uncertified mechanic we would take their money, fail the car, and send them on their way over and over until they wised up and got with the program.
 

VAL

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Looking at your sheet it appears that you are running rich during the loaded test thus the high CO reading. Please provide us with some more information:
Do you have a catalytic converter?
What are you running for an ignition system?
What is your base ignition timing set at?
What port is your vacuum advance connected to ported or manifold?
Have you done any tuning on the carburator like rods, jets or springs?

With this info collectively we can all chime in to help.

I'm running dual exhaust with two catalytic converters, Ignition is stock HEI, vacuum advance is connected to manifold port, not sure what the timing is set to.
The carburetor has always run rich since new. For the past 4 years, I've been able to pass emissions, by completely closing off the idle mixture screws, and turning the idle way up. after it passed, I'd just reset the carb to where it was. This time I didn't get away with it. I have noticed that my accelerator pump is leaking a little bit, and my carb is dark with carbon build up when I pulled off the air cleaner.
 

VAL

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It's a real crap shoot trying to tune for emissions without the proper equipment. George is right, you're running rich under load. You need to lean it out, but as you do so the hc readings will climb. You have some room to work with there but whether or not the co can come down below 1.20 without exceeding 220 on the hc side is anyone's guess. That's why being able to see the readings as you tune is necessary. In Cali, they didn't used to charge for a retest and guys were going out in the parking lot, tweaking the carb a bit, and getting retested to see what difference it made. I remember this one guy, I tested his VW bug over thirty times in one day. It finally passed, but the state got wise to that crap and started charging $7 for a retest so it was cheaper to go pay a mechanic. I don't know how AZ. does it, but in Cali if you went to a state certified "Blue Shield" mechanic and he certified he had tuned the vehicle to the best of his ability, you would get a certificate allowing registration even if the vehicle didn't pass emissions. It was sort of a good faith waiver. If people did it themselves or went to an uncertified mechanic we would take their money, fail the car, and send them on their way over and over until they wised up and got with the program.

Here in AZ, if you fail emissions, you can get a second test free, if done within 60 days of failing. After that, it $12.25 for another two tests and etc.
 

Georgeb

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I haven't got a good enough grasp on ignition timing yet but I wonder if an adjustment to the timing and a temporary increase in ethanol in the fuel would get you by. I remember using isopropal alcohol in a rather strong dose to drop my emmissions far enough to pass.
Here is a document that discusses this exact subject. The second page.
http://www.tf.llu.lv/adzl/publikacijas/2014-01_Gailis&Co.pdf

Still a crapshoot tho.....
 
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VAL

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I'm gonna do a rebuild on it, I've been wanting to go in and change the jets for the longest now, gonna go with 95 primaries and 92 secondary, hope it does the trick Its been 4 years since I put that carb on, from what I've read online, it looks to be time to freshen it up. Has anybody ever had any luck with color tuning, to pass emissions?
 

VAL

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From the looks of it, it has a couple of leaks. The pump, and I still cant figure out where that other gummed up area right under the pump is coming from. Do all Edelbrocks get this dirty with normal use?
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Georgeb

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Is there a crack at the bottom of this screw boss?
 

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VAL

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Is there a crack at the bottom of this screw boss?

And the nightmare continues!:banghead: I'm guessing its from the heat. It wasn't like that a few months ago.
 
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crazy4offroad

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From the looks of it, it has a couple of leaks. The pump, and I still cant figure out where that other gummed up area right under the pump is coming from. Do all Edelbrocks get this dirty with normal use?
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ATTACH]
Yes they sure do. I'm looking to replace mine with a known good q-jet before long. Mine did great for a long time but like all things they wear out. Mine is in similar shape and I debated rebuilding it (which would have included the throttle shaft bushings, accelerator pump seal, gaskets, etc) then all the tuning of rods, jets and springs to try to make it right, or just replace the carb altogether. The reason I'd like to try going with the q-jet is mechanical secondaries just dumping gas in the cylinders at WOT whether or not the a/f ratio is right, or vacuum secondaries that open as engine demand dictates. My biggest problem was finding a way to adapt (properly) a spread bore carb to a square flange intake. Let's just say I have one, but it is going to need a little burr bit work to make me feel alright that the rear butterflies aren't going to hang up on it. However I have the luxury of my square not being my daily driver. You can definitely lean it out with the jet change, I think 0.098 primaries are stock, what is your current setting? I'll attach the tuning chart if you dont have it already. If you have stock 1459 rods the 0.095 jets would set you at 12 on that chart. If you have 1456 rods it would put you at 7, a little more conservative on the lean side. How far out of spec did the smog report read your truck running?
Is there a crack at the bottom of this screw boss?
I dont see one? I see the line separating the top from the main carb body (horizontal).
 

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rich weyand

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I tuned mine with an AFR meter. Here's the setup I have. It's probably close for you.

secondary metering jets: Edelbrock 1426, 0.095" (stock jet)
primary metering jets: Edelbrock 1425, 0.092"
metering rods: Edelbrock 1461, 0.065" cruise, 0.057" power
step-up springs: 8#
 

VAL

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Well, I was worried I had a Crack, turns out them bolt holes go all the way through the top half of the carb. I got in there and took a pic, man what a relief. I'm guessing the gasket is is toast.
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VAL

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I tuned mine with an AFR meter. Here's the setup I have. It's probably close for you.

secondary metering jets: Edelbrock 1426, 0.095" (stock jet)
primary metering jets: Edelbrock 1425, 0.092"
metering rods: Edelbrock 1461, 0.065" cruise, 0.057" power
step-up springs: 8#

Yeah, I'm waiting for the rebuild kit to get here on Monday to pull off the carb. I went and bought a set of 92 jets for the secondaries, gonna put the 95s in the primary. I did however pull the metering rods out, the number on them is 7547. I can't make out the spring color, to know which one I have. I'm hoping the rebuild and jet change will solve my emissions issues.
 

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