57 T-Bird Holley Carb problems

[Chris Bergquist]

I just replaced the carburetor on my 57 T-Bird (312) with a rebuilt
Holley (1273-2S 0276 ?) and have a couple problems. First, the idle
circuit middle adjustment don't seem to have much effect. I have them
screwed out only about a quarter to half turn and I still can't get the
idle down. The idle adjustment screw
is all the way out. Second problem, at 35 mph, and up, I have a BIG
flat spot. It feels like the linkage is stuck, but it's not. If try to
accelerate by easing into the throttle I have to go all they down until
I hit the kick down linkage. If it down shifts it goes like hell. From
a stop it will accelerate all the way up. The
accelerator pump works great from a stop. There is no hesitation (the
reason I swapped out the old carburetor).

Can the power valve be bad? Can it be intermittent?

The idle adjustment problem I've had since I installed the carburetor,
the flat spot started on the freeway about 30 minutes into a short
freeway drive.

Chris

Replace NOSPAM with chr...@us.ibm.com

[Whole Lotta Tom]

I don't know what model the replacement is, but if it is an emmisions carb,
the screws on the side adjust an air bleed, not the idle mixture as on the
old Holleys. As for the dead spot, your power valve may be one that opens
too late for the engine. Try an 8.5 or 9.5. The stock power valve is 6.5
and I could never use them. Why did you not rebuild the stock carb?

[gee...@inreach.com]

Chris Bergquist wrote:
>
> I just replaced the carburetor on my 57 T-Bird (312) with a rebuilt
> Holley (1273-2S 0276 ?) and have a couple problems. First, the idle
> circuit middle adjustment don't seem to have much effect. I have them
> screwed out only about a quarter to half turn and I still can't get the
> idle down. The idle adjustment screw
> is all the way out. Second problem, at 35 mph, and up, I have a BIG
> flat spot. It feels like the linkage is stuck, but it's not. If try to
> accelerate by easing into the throttle I have to go all they down until
> I hit the kick down linkage. If it down shifts it goes like hell. From
> a stop it will accelerate all the way up. The
> accelerator pump works great from a stop. There is no hesitation (the
> reason I swapped out the old carburetor).
>
> Can the power valve be bad? Can it be intermittent?
>
> The idle adjustment problem I've had since I installed the carburetor,
> the flat spot started on the freeway about 30 minutes into a short
> freeway drive.
>
> Chris
>
> Replace NOSPAM with chr...@us.ibm.com

Have we talked before? If not, why don't you read my Holley carb tuning
page at http://home.inreach.com/geewhiz/carb.htm and get back to me.
Can you find the LIST number on the carb? It's on the airhorn of most 4
barrel carbs. Carb advice is free.

Gerard
--
BOB Oil Recovery System: http://www.bob2000.com
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Geewhiz Homepage: http://home.inreach.com/geewhiz/4277.htm :
Fast Ford cars, ATV's, Rockets, & A Tribute to My Late Father

[Chris Bergquist]

Tom, it's an original 57 T-Bird carb and has the original idle adjustments,
it's not an emission carb. I'll check the power valve. I ran out of time
Sunday afternoon.

The original carb had a bad hesitation, I tried to rebuild it without any
luck. I took to a T-Bird restoration shop and they tried without any luck.
This carb came off a running car and I was told it had no problems. I trust
the guy that sold it to me. I picked it up for $50. A very good price for an
original Holley carb.

Thanks for the advice.

Whole Lotta Tom wrote:

> I don't know what model the replacement is, but if it is an emmisions carb,
> the screws on the side adjust an air bleed, not the idle mixture as on the
> old Holleys. As for the dead spot, your power valve may be one that opens
> too late for the engine. Try an 8.5 or 9.5. The stock power valve is 6.5
> and I could never use them. Why did you not rebuild the stock carb?
>

[CJ Shakoske]

Just my opinion, but it sounds like a vacuume leak. Check the gaskets.

[John Leipold]

This might raise the ire of Holley fans, but get an AFB. Holly is the best
racing carb ever made, but in my exoerience it SUCKS as a street carb. Use
an AFB on the street. Opinions are like assholes; everyones got one!

John

[Whole Lotta Tom]

John Leipold wrote:

> This might raise the ire of Holley fans, but get an AFB. Holly is the best
> racing carb ever made, but in my exoerience it SUCKS as a street carb. Use
> an AFB on the street.

Yes, the AFB is simple, easy to tune, not messy at all and dead reliable. Set
it and forget it. The Holley is original on the Ford T-bird two-seater, but
the AFB, or the Edelbrock Performer version of it, is a great alternative.

> Opinions are like assholes; everyones got one!
>
> John

Why are you nullifying what would otherwise have been good advice? Stand
proud, AFB man!

[Hemi4268]

Hi

Sounds like a big vacuum leak. It's hard to rebuild these old Holley carbs
without machining the base. Many of these carbs are warped and will not take a
rebuild unless they are machined.

Larry