Tuning a 1406 Edelbrock Carb with Bog

[74Runneer]

I have an eddy 1406 600cfm carb on my 318. Rpm intake, 302 heads, headers, dual exhaust, ~340 cam, FBO ignition. When I slam the throttle pedal from dead stop or light cruise, the car bogs out and nearly dies. It idles great, cruises great and is great at WOT, but bogs down at the transition to power mode. I'm thinking it's either an accelerator pump issue or a step up spring issue.

Has anyone dealt with a similar situation? Which should I try first? If I should try accelerator pump first, which pump should I try the 1470 or a stiffer one?

16 mmhg at 600 rpm, looks like the carb has the blue step up springs

Thanks!

 

[khryslerkid]

Go with the orange one, 1467

 

[74Runneer]

From my understanding, 1470 is the stock pump, but what is the difference between 1468 and 1467?

 

[khryslerkid]

From my understanding, 1470 is the stock pump, but what is the difference between 1468 and 1467?

1468...Carbs 1412, 1413, 1812, and 1813
https://www.summitracing.com/parts/...MIgZe6zceb3gIVlq_ICh0JfwamEAQYAiABEgLmGPD_BwE


1467...Performer Carbs 1407 and 1411
https://www.summitracing.com/parts/...MIkuaUsMib3gIVE4GzCh2opwfgEAQYAiABEgKD7_D_BwE

I have two 1406 Eddies. The 1467 pump works great. The 1407's (blue one) are junk!

 

[74Runneer]

Alright, I'll try that!

 

[toolmanmike]

Check out some of the threads over at FABO. Lots of carb and 318 tune info there.

 

[threewood]

The 1468 has a stiffer spring so it gives a bit better shot without compressing. Buy a couple of them as I consider them a wear item.

If you are bogging, what hole is the pump arm in? Closer to the pump, more shot, farther away, less shot.

How old is the carb? Ever been rebuilt? They are super easy to break down to check all the passages for trash, check float level and clean or replace fuel inlet spring.

 

[rumblefish360]

I have an eddy 1406 600cfm carb / I'm thinking it's either an accelerator pump issue or a step up spring issue.

Thanks!

Spring first, spring rate is 1/2 of the engines vacuum. The pump cluster. The pump shot arm should be in the closest hole to the carb to start. You may actually find that moving it back a hole to be a help.

Also tune your ignition. More advance is better IF you can use it.

The biggest problem with the AFB carb is the uncontrolled weighted secondary door. The engine demand can top the door open enough for the big but the engine can not I nest it all and that lets the door slam shut and bounce back open to wide again when the engine recovers.

AFB ‘s are actually better slightly undersized.
The AVS with its spring loaded secondary door is a better unit to use since you can tighten up the door for a delayed response.

 

[71Beeper]

The 1406 carb is an emissions type carb. The metering rod settings for them make them lean.
Go to the Edelbrock website and print off the users manual for thier carbs.
Then use the metering rod settings for the 1405 carb, not the 1406.
The 1405 carb is the performance version of the 600cfm carb. You will get better results using the 1405 settings .

 

[74Runneer]

I should have mentioned, I tried the accelerator pump linkage at all three spots and couldn't really tell a difference. The rich hole closest to the carb might have been better, but not by much.

The carb was rebuilt 4 years ago and probably only has 300 miles on it. I cant remember if the kit had a new accelerator pump or not (I had a shop rebuild it). The car has always had a bog under immediate heavy acceleration for as long as I've owned it (8 years)

I ordered both the tuning kit and a 1467 pump. I'll probably start with a spring because that's the easiest and then try the pump.

 

[Darter6]

And last but not least, Edelbrock makes 3 different squirter nozzles in .024,.033 and .043 sizes. part # 1475 for all 3.

 

[Ranger16]

Back to basics. Remove the air filter and look down the carburetor bore while moving the throttle lever to WOT. If the accelerator pump is good, you should see two streams of raw fuel squirting into the bore.

 

[Bee1971]

At 16" hg of vacuum in your first post

Get rid of the blue step up springs on the metering rods 3 hg - Way to light

Try the pink step up springs at 7 hg or the plain steel at 8 hg and see if that helps first

Others have talked about the accelerator pump

Pull the air cleaner off without the engine running and manually stab the throttle linkage on the carb , how does the pump shot look ?
Coming out of the nozzle on both sides

Float level is just as important , very very important with these carbs

 

[Bee1971]

Man I type slow while watching tv

Ranger 16 basically same thing I was trying to type

 

[toolmanmike]

Here's a good video:

 

[khryslerkid]

I stated that I have 1406 but I have the 1405

Here's the different factory jetting, and springs

1405 metering jets pri .100 Sec .095

1406 metering jets pri .098 Sec .095

Metering rods 1405 .070 X .047

Metering rods 1406 .075 X .047

Step up springs 1405 orange

Step up springs 1406 yellow.

 

[toolmanmike]

I stated that I have 1406 but I have the 1405

Here's the different factory jetting, and springs

1405 metering jets pri .100 Sec .095

1406 metering jets pri .098 Sec .095

Metering rods 1405 .070 X .047

Metering rods 1406 .075 X .047

Step up springs 1405 orange

Step up springs 1406 yellow.

Yep, 1406 is set up for economy and the 1405 is set up for performance. Thanks for the numbers.

 

[74Runneer]

Are you guys running the 1405 rod and jet settings (either on a 1405 or 1406) on a 318? My engine seems to run really well outside of this bog, but I'm wondering if it would be better with a 1405 tune? I'll probably have to get an O2 sensor to be sure.

 

[khryslerkid]

Are you guys running the 1405 rod and jet settings (either on a 1405 or 1406) on a 318? My engine seems to run really well outside of this bog, but I'm wondering if it would be better with a 1405 tune? I'll probably have to get an O2 sensor to be sure.

If it were I, I would change the accelerator pump first and see if it takes care of the bog. In my own experience, I had the 1470 (blue) pump in my carbs. Its what the rebuild kit had in it. After two months the rear carb was loosing it squirt. Replaced with the 1467 (orange) and the acceleration was much better than ever.

If that solves your problem then you can move on to your carb tuning. Best thing is to read your plugs to tell what you have. They will show your rich/lean and also how the timing is set.

 

[74Runneer]

I ran my car for a few minutes to make sure the fuel bowls were filled up and then pumped my accelerator pump linkage and to no surprise, no fuel came out of the accelerator pump nozzles. Not even a little bit. So it looks like it's probably a bad accelerator pump. Is it possible that the accelerator pump chamber isn't filling up because the floats aren't set up right or is there another passageway to the pump reservoir that could be clogged?