Carb questions

[dgie]

I have an edlebrock 1406 on my 400 and am getting a weird noise from it, any ideas what this could be? It also idles strange and sometimes backfires through the exhaust. I think I have heard in the past, that backfires through the carburetor are timing issues and backfires through the exhaust are fuel issues, or is this wrong? Lot of questions, I know.

[RD]

what does the noise sound like?

secondly, check for vacuum leaks at the carb base gasket, or the rear of the carburetor as there is a plug that needs to be there.

if you are getting backfires, you may be too lean.

[MoParMetal]

i also have the same problem with the 1406 Eddy. except it fires up and then it floods the primaries. also sounds like its sucking air through somewhere else that it shouldn't be.


sorry for the 

[dgie]

I am pretty sure the plug was put in, I will double check to see. The sound, sounds like a knocking sound and is coming from the carb. Lean would backfire through exhaust?

[dgie]

I have further information in case anyone here can help with my question. I found that the noise is not emanating from the carburetor instead it is coming from the cutouts on top of the heads. I do not know what they are for but I know the one on the passenger side goes to the thermostat thing that is used on the old manifold choke part. The new intake is an edlebrock 4-barrel performer intake. The holes are exposed with this new intake, where with the old one they were covered by the intake. Also I spray carb cleaner in the passneger side port cutout part and the rpms change. Are these things supposed to be blocked off somehow. I also did a compression test and came up with this:

Driver's side
#1 115
#3 95
#5 105
#7 95
Passenger side
#2 90
#4 110
#6 85
#8 115

[dgie]

Any takers, anyone Bueller, Bueller.....

[uud looz]

I dont have any answers for you but the exact thing is happening to mine, (440) Mine is running very lean at idle and have very low vacuum .I've been chasing this leak and can't seem to find it. the idle on mine also flares when I spray carb cleaner in these ports. I too have the 1406 carb with a stock manifold. I replaced the intake gaskets twice,(no help) I just replaced the intake this week with a eddy performer, new intake gaskets and carb base gaskets (little to no improvement) I have a new 1411 carb coming hopefully that will change things. Hopefully someone here can help us both.

Are you talking about these ports?