Thread: 3X2 Carburetor idles too rich/406 engine

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I own 2 1962 Ford Galaxies with 3X2 carb setup on a 406 engine. I have the same problem on both engines. One is a lot worse than the other. While the car is idling, it is extremely rich. I have had this problem on one of the cars for approximately 40 years. I have tried various things from people's suggestions, but none have been successful. I have changed the power valves from 6.0 to 2.0. They have Holley carburetors on them. Any suggestions will be appreciated.

Progressive linkage on the carbs???? Are you idling with just the center carb? First things come to mind are choke setting and float level?

idle past the idle slot .mix screws out to far .if not that you could drill out the idle air bleeds make sure the other carbs are not driping fuel in

Originally Posted by pat mccarthy

idle past the idle slot .mix screws out to far .if not that you could drill out the idle air bleeds make sure the other carbs are not driping fuel in

Oh yeah!~!!!!! Forgot about that one Pat!!!! Had to drill extra holes in the butterflies on the center carb on a 440 6 pack, also had Holley carbs....

Originally Posted by Dave Severson

Oh yeah!~!!!!! Forgot about that one Pat!!!! Had to drill extra holes in the butterflies on the center carb on a 440 6 pack, also had Holley carbs....

well you could do that if he is all most past the trans slots. but if you could crack the other two carbs a very weee bit that could lean it up but your idle will go up as well .if you drill the idle air bleeds out the next size up that can help just keep going up till she were you want it if every thing is good thats what i have done

Besidess making sure the end carb aren't leaking you might also want to check and see if the throttle plate on the end carbs are fully seated when closed and throttle shaft bushing are good.

If your end carb's aren't leaking, I'm with Pat, you have the idle screw in to far and your to high on the idle slots, if your you can't set your idle by adjusting your mixture screws, you'll need to drill the mixture screw holes a drill bit size bigger(If you carb's mixture screws adjust air, and not adjust the fuel mixture), to allow more air in (you may have to do it a couple of times to get the air flow you need). set your butterflies with a feelers gage and don't touch it, set the idle with the mixtrue screws.
That is if your not leaking in the end carb's anywhere, like Mike say's.
I have run 3X2's for years, and never had problems, and everyone I knew couldn't get them right & I would fix them for them.

Set them with the linkage off, then after they idle & run right on the center carb, Then put the linkage back on and see if they still run right.

Pat

[Thanks for the info. I will try all of your suggestions.

62 Galaxie

www.hptrends.com

I had a '63 with the 3x2 set up - and used it for many years on that car as well as others - I finally sold the setup a couple of years ago for quite a lot You can change power valves all day, but one fart back thru the carb when you start the car and it will kill them instantly. You need a new 6.5 power valve AND a new pair of gaskets for the float bowl and jet plate - they leak. Also, it has also been recommended above to move the end carbs just off idle - necessary. Another item, make sure that the end carbs do NOT have power valves, as some '62s snuck by with them installed (quality was not job one then). The holes need to be plugged after removing the PV's if there.

check the trottle shafts. they could be worn. causing the idle to be reatic. i've run into this problem with holleys in the pass. pony carb. can fix them.

There's no reason that it can't be fixed to idle correctly. After all the primary is just a two barrel carb.

The others have good suggestions, but here's one that we used to find common "back in the day" when I did tune-up work at a Ford Dealership. The body on Holley carbs (both two and four barrel) warps/distorts because of "over tightening" of the float bowl screws. It can be checked with a straight edge and if found warped, you can use a flat body file to true it up.