1971 Thunderbird Carb

[oldkid1940]

Hello! I recently got my first Thunderbird as a first project car. It’s in great shape, ran until my starter went kaput two days ago, and has a rather easy list of issues. It’s biggest issue when driving it is a horribly weak throttle, rich run, and a guaranteed stall with a hard brake. I suspect the carburetor to be the issue, (most likely the throttle body). As I’m currently ill, and waiting for my next paycheck, haha, I can’t really do much other than research. I wanted to ask, did the 7.0L 429 come standard with a 4 barrel, carb, or is it possible that there is a 2 barrel instead? I’m just trying to learn the car as I can, and as much as I can, I appreciate any advice! I would also like to ask, if on one of the power windows, the motor grinds and the window doesn’t move, if you would suspect a motor, regulator, or even a switch issue?

https://www.dropbox.com/s/h81yj676kefhq ... 1.JPG?dl=0

[cacockrum]

A quick Google search showed the 4-barrel (4V) to be the preferred choice for the 429 engine as it provided significantly more horsepower, but the 2-barrel (2V) was available - mostly for trucks. I’m no expert, but I don’t know of any TBirds that came with a 2V carb. While restoring my ’68, I took my original 4V carburetor to my favorite carb restoration guy, and he told me that while the Autolite 4100 4V carb used on earlier 390 and 428 Fords was a good unit, the stock 429 4V carb was notorious for warping, and was not worth trying to restore. Instead, he suggested an Edelbrock AVS2. I couldn’t be happier with its performance.

[oldkid1940]

Thank you for the information and the suggestion, I will be sure to take it into account! I wouldn’t be surprised if warping is part of my issues with throttle and idle, I’ll hold onto the original just in case but I’ll see what I can find. If Edlebrock offers a compatible with the heat operated choke that would be perfect, I’ll do some snooping.

[RAVEN]

Why not before you drop the 4100, check and see if it is warped. a simple lay down on a proven "FLAT" surface. It could be other factors like float levels or power valve or even a linkage issue. Nothing checked is a possible loss.

[cacockrum]

Raven,
Raven:

Why not before you drop the 4100, check and see if it is warped.

CACockrum:

I took my original 4V carburetor to my favorite carb restoration guy, and he told me that while the Autolite 4100 4V carb used on earlier 390 and 428 Fords was a good unit, the stock 429 4V carb was notorious for warping

I'm assuming that since the '68 through '71 Birds used the new 429 engine, they all also used the same (troublesome) Autolite 4300 carburetor. Although, I've read that Ford made many changes to the 4300 during it's lifetime. The 4100's are a much better carb, and I would have had it restored had it been a 4100.
Art

[Alan H. Tast]

Why not before you drop the 4100, check and see if it is warped. a simple lay down on a proven "FLAT" surface. It could be other factors like float levels or power valve or even a linkage issue. Nothing checked is a possible loss.

The original carb for the '67-'71s is an Autolite 4300 - much different from the '66-prior 4100. It was not one of Ford's better ideas. It was actually introduced on late '66 full-size Ford '7-Litre' models with the 428, then used in '67-forward on T-birds with both the FE-series 390-428s ('67) and the 385-series 429s (except for some high-performance versions) from '68 through '71 and on '72-'76 460s in revised form, i.e. the Autolite 4350.

Left Front view of Autolite 4300 (TSB 42 - Jul 15, 1966)

Right Rear view of Autolite 4300 (TSB 42 - Jul 15, 1966)

Top view of Autolite 4300 (TSB 42 - Jul 15, 1966)

Exploded view of Autolite 4300 (TSB 42 - Jul 15, 1966)

Yes, it was improved over the years, but it's still a finnicky carb to work with. Doing some online searches for Autolite 4300 may yield some tips or troubleshooting suggestions, along with people who specialize in rebuilding them. Better yet, if you own a '69-'71, you would be well advised to buy the entire Shop Manual set (5-volumes) for your specific year. While it includes all Ford/Mercury/Lincoln cars, it is a wealth of information and a good way to educate yourself about what all goes into your 'Bird.

[dieselman2000]

I actually just replaced my 3rd 4300 for a Holley 4 barrel (0-1850S). That being said, a Holley 4412s (2-barrel) should be a direct bolt-on with the 20-2 ball stud kit. Currently working on jetting to fix a richness problem.