Surge/Miss 2 x 4 Carter AFB

[Jeff Sine]

I am fighting a Surge/Miss through entire RPM range on my 409 2 x 4 Carter AFB Engine
I Have NEW Pertronix Ignitor III Distributor, Coil, Wires, AC Delco 43XLS spark plugs and the Carbs Overhauled
After a long roadtest I pulled the spark plugs and found the forward 2 cylinders on both banks #s1,2,3,4 coated in black soot!
I think this is a carb calibration/set-up problem?
Is there a Calibration proceedure?

 

[wristpin]

Id start by checking front float level. Then ensure accelerator pump circut is operating properly...IE it works when accelerating not ALL THE TIME

 

[Jeff Sine]

The Float level is correct and the accelerator pump is squirting fuel when I actuate the throttle. I'm thinking that the Black carbon like soot on the plugs is a result of a rich condition. It seems that there is not enough air reaching the front cylinders. I think there must be a balancing or setting procedure for the 2 Carter AFB carbs

 

[IMBVSUR?]

Were any of these conditions present before the carb rebuild and the New distributor?

 

[MRHP]

Check your firing order.

 

[Jeff Sine]

MRHP
18436572 is the firing order I use. This is on the intake.

 

[Jeff Sine]

IMBVSUR
The Distributor was replaced when I purchased the car
to eliminate the old points and upgrade the ignition system for a lack of power only to find that the camshaft was extremely worn which resulted in a engine rebuild. The engine was bored and stroked to approx. 475ci with a mild cam. The carbs were reconditioned soon after the rebuild. This Surge/miss has been prevalent sense the Engine rebuild.

 

[La Hot Rods]

What AFB carburetors our we talking about, original or of the shelf?

 

[blkblk63ss]

What air cleaner are you using? Are you using a automatic choke? Could your choke be possibly closing on cruse? Just wondering? Like your car, i was eyeing it before you bought it!!!

 

[Jeff Sine]

La hot rod - The carbs are original
blkblk63ss - Factory air cleaner, factory heat pipe choke. I don't think that the choke is closing.
I do like my car! Thank You! I did not think I was going to have to do a complete engine rebuild. If you read my story you will see why I purchased it.

 

[La Hot Rods]

Check for vacuum coming through the front carburetor at idle.
It should act just like the secondaire on a four barrel.

 

[skipxt4]

Are you using the metal shims, under your carbs?

 

[Jeff Sine]

skipxt4 - No there is 1 gasket between the carbs and the factory intake.

 

[Jeff Sine]

Well have you ever heard of the FWFWI repair? It is "Fixed While F**king With It!"
That seems to be what has happened hear. A friend came over and we started Brain storming (Not much of a storm)
We replaced the Spark Plugs with a Hotter plug AC Delco R44XLS, reset the rev limiter to 5,500rpm on the Pertronix Ignitor lll, replaced the Distributor cap. set timing and set the carb mixture screws, and Base idle speed and the engine smoothed out and the Surge/Miss is GONE! I don't know which of these procedures was the fix or if it was the combination of 2 or all of those things! If I was to bet I think that going through the REV limiter setting procedure is what corrected the problem. When we initiated the rev limiter setting it took 3 times before it responded. Well whatever the trouble was it is gone now.

 

[La Hot Rods]

That's good news.

 

[blkblk63ss]

That's was probably all of the things you did to fix it.

 

[55Brodie]

White man voodoo.

 

[IMBVSUR?]

I also had some issues getting the Rev limiter set on the Billet Pertronix III distributor.