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Mon Mar 01, 2010 9:56 pm

ok so ive spent dollar after dollar on my 72 Squareback Converted to Carbs

So heres the list of new Parts
Dual ICT Carbs
009 dizzy cam with new points cap rotor exc
pugs
wires
all new fuel lines and filters

Ok so Timing is good carbs were synced points were gapped valves adjusted the works!!!

The damn thing keeps back firing through the #1 #2 carb only under normal driving. Full Throttle this thing runs awesome but i cant granny her!!! never back fires out of the #3 #4 Carb

Any thoughts??? ive been bangin my head for days with this thing!!!

Mon Mar 01, 2010 10:01 pm

New or used carbs?

Sounds like something in the idle jet, make sure to pull it and clean it. Even new ones can have something in there.

Mon Mar 01, 2010 10:05 pm

Brand new Carbs! were is the idle jet located?
i gather i have to take the carb apart but theres a few jets in there

Mon Mar 01, 2010 10:16 pm

I'm typing this from my phone or I'd give you a link to the exploded view since you should check them all. Doesn't take long on an ICT. In the meantime google weber redline 34 ict and it should take you to their page.

Another thing to do is take some brake cleaner or carb cleaner and spray around the intake and carb gaskets. If you hear the idle raise or miss you know you have an air leak.

Mon Mar 01, 2010 10:18 pm

What gaskets did you use between the intake manifolds and the head. I hope not the metal ones that are sold for dual port bugs. Those will leak with T-3 manifolds. You need the thicker paper ones. Or make one from cereal box cardboard.

Mon Mar 01, 2010 10:48 pm

i used paper gaskets Metal ones are lame. ill spray the manifolds in the morning and pull the carb apart. thanks for your time guys ill report in the morning!
Thanks Again

Tue Mar 02, 2010 4:16 pm

no leaks plugs are good re synced same issues.

seems like its not advancing from time to time could this be an issue with a brand new Dizzy?????

Tue Mar 02, 2010 4:44 pm

how is it jetted?
are the jets the same?
lean on one side fat on the other?

Tue Mar 02, 2010 7:28 pm

havent touched the jets i assume there the same ive played with mixture screw with no help to the issue.

Tue Mar 02, 2010 8:33 pm

where did you gets the carbs from. i know cb actually changes the jects for type three. could it bee you just have wrong jets??

Tue Mar 02, 2010 9:06 pm

Speaking of your distributor, how did you time it? An .009 needs to have the timing set at about 3500 rpms and then should be about 30-32 degrees BTDC, if I remember correctly. Could be part of the issue, and then re-syncing the carbs, adjusting the idle as well as the air intake. Here is a link to setting your carbs up.
http://www.cbperformance.com/weberict.asp

Tue Mar 02, 2010 9:15 pm

Do you have a balance pipe/hose between the 2 intake manifolds?

Tue Mar 02, 2010 10:31 pm

i bought the carbs from EMPI they are the EPC 34's i have an account with them for the my Parts Store there is no provisions for a balance tube.
timing was set by a local shop they timed it at idle its timed at the second notch from the left at idle. may be a little retarded? ive gone through both carbs theres nothing in the idle jet or the carbs at all.

Tue Mar 02, 2010 11:03 pm

just thought of something....do you have an electric or mechanical fuel pump? and do you have a fuel pressure regulator? Not sure if the Empi 34s are the same but on weber 34s they can't have more then 3.5psi of fuel pressure.

Tue Mar 02, 2010 11:16 pm

i have an electric pump and its regulated to 2 PSI

Wed Mar 03, 2010 8:38 am

Something I found via a google search.
"EMPI carbs (own design) – built in China. Unlike Interco and its affiliates -
EMPI does not brand these as “WEBER” carburetors – they are branded as what they are - EMPI carburetors. Visually the EMPI carbs closely resemble the well known weber carburetors.
Known EMPI models of carburetors
· EPC 32/36e
· EPC 32/36m
· EPC 32/36a
· EPC 38/38e
· EPC 32/36f
· EPC 34
· EPC 40 HPMX
· EPC 44 HPMX"
One thing I have experienced with EMPI is that they have no technical support for their parts, and usually don't provide installation instructions.
I am sort of guessing now that your carbs are the problem.

Wed Mar 03, 2010 9:01 am

what type of fuel regulator is it? and 2 really is a bit low, I'd run it at 3psi

Wed Mar 03, 2010 9:22 am

im thinking its carbs too but itle take weeks to get new ones out of empi!!!!!!!!!

Wed Mar 03, 2010 9:22 am

the regulator is a holley red ill bump it up and see what she does

Tue Dec 27, 2011 10:11 am

The problem is in the idle jet circuit. if the idle jet is too lean, down low you will get a pop until the main jets come on. you can still have a vacuum leak too such as a cracked base. those carbs come with a 55 idle jet. step up to the 60 jet then 65 if the problem gets better but does not go away. i had the same problem