carb and choke question

[frogy]

Hi folks,
I have a 1972 F100, 4x4, manual (4 gears including a granny gear), 360ci V8, with a Motorcraft (autolite) 2100 D2TF-AB 2 barrel carburetor.
A few months ago, I had a wire that burnt which required me to bring the truck to the shop. While it was in their care, I asked that they changed the choke heat tube (going from the exhaust manifold to the choke) as mine was broken.

A couple weeks ago, I tried to use the truck and it would die as soon as I would get to a stop. After checking the timing, spark plugs and fuel filter, I checked the choke. I found that when the shop installed the new choke heat tube, the completely cross-threaded and ruined the threads on the choke side (see blue arrow in picture, although I re-threaded it since) and the connection was completely loose.
Since i needed to use the truck, I installed another choke that I had on a shelf (sorry, I didn't take a picture of it before installing it). The difference between the replacement and the original choke, is that the replacement has some sort of "piston" moving in/out of the chamber that the yellow arrow points to. That "piston" is linked to the moving arm that the green arrow points to. Only one of the 2 holes (see red arrows) are present.

My question is: is that a viable choke assembly for my carb? Would it perform correctly?
What I have noticed is that even after running for 2-3 minutes, tapping the accelerator doesn't drop the carburetor from idling fast. Before, i would start the truck, it would idle fast while warming up, and then i would gently tap the accelerator and it would drop to a slow/smooth idling.

Finally my second question is: do you know of good modern (ie more precisely build and tune-able) carb that doesn't have fuel bowls mounted on its sides ? I spend time searching online and cannot find anything. I'm not considering building this truck for power and speed, I just would like a reliable, efficient carb (injection systems are too spendy for me).

Thank you for your help,
Ciao
Ivan

[Mach428]

I'll try to respond to all of your concerns.

First, there is no difference in operation between the two choke assemblies mentioned. The piston style was a simple a way for gravity to assist in opening the choke. If your truck is not warming up very fast (very cold weather) the choke will not open as quickly as you may think.

Second, when you try to kick the idle down, what position is the choke plate? If you manually open the choke plate, you should be able to recreate the choke operation and the fast idle cam should go to the second position. There may be something binding.

Finally, it is my opinion that the Autolite 2100 carburetor is far superior to any other brand out there. I have had my original in service for 50 years

[frogy]

Hi Mach428,
Thank you for replying to my post and sharing your opinion.
Since my first post, I played again with various settings and found a sweet spot. The carb now idles nicely and doesn't die when coming to a stop.
The only issue left is the dashpot: it's gone and despite spending 2hrs online I cannot find one.
Those are not being produced anymore?
Thank you

[Mach428]

You most likely do not need one. My truck never had one. The springloaded type were used to gradually allow the carburetor to decelerate. Sounds like you are good to go

[frogy]

Thanks man,
ciao