Looking for any help with the electric choke set up on a 73 F100 302. Not sure what all needs to be connected to the choke. Also could the electric choke coil be shot? Any help would be great..would like to be able to drive this summer!!!

 

First off, I'm not sure if your choke is at all like the one on my '79 302 w/Motorcraft 2150 carb. But on the '79 it is not exactly what I'd call an electric choke - it is a 'Hot Air With Electric Assist Automatic Choke System'. You still need to have the hot air tube connected to the exhaust manifold for a 'Hot Air' source. The tube should have an insulated sleave over it to keep the heat in the tube so that the heat makes it to the choke cover and is not disipated in the cool air from the fan wash. Make sure the tube is not plugged up with "stuff" (technical word.)
Also, the heat box in the exhaust manifold should should have a fresh air tube connected to the back of the carb so that the hot air pulled into the choke housing is replaced with f-i-l-t-e-r-e-d air, as in air that ends up going through the air filter before it gets to the heat box. (Prevents 'stuff' from getting in Hot Air tube and the choke housing.)

The electric circuit within the choke cap consists of a set of electrical contacts and a thermal switch. Its power source is the alternator stator. At cooler temps the choke cap circuit is open so the only heat source is the Hot Air tube. When the choke housing gets to a predefined temp, the electrical contacts within the choke cap close and current from the alternator flows through the choke heater element. (Side note - the reason they power the choke heater from the alternator is becasue if the engine stalls when the heater is activated, current stops flowing through the choke heater element since the alternator is no longer turning.)

When the choke heater element is activated, what it is doing is 'assisting' the heat tube in its funtion of warming the choke cap spring so that it can open the choke faster than if the choke was to depend on the Hot Air tube by itself for heat. Ergo: the descriptive title - "Hot Air with Electrical Assist".

I'm hoping some one will correct any errors in my post. Have at it "TheBoys" and hope you have it running by the summer.

 

Thanks for the help. It gets me a starting point...From what I can tell, it does not have a place for a hot air tube to hook up to the choke or has never had one hooked up...was that orginal for the truck?? Any pics or diagrams of this set up would be great so that I can compare to what I am seeing in the truck..Also should I buy a new choke coil???
Thanks
TheBoys

 

It was original on my '79. I am guessing it was original on your '73. You really ought to try and locate a factory service manual - it'll show you everything you want to know about your truck.

Is your carb a 2150? You could look here,
http://home.earthlink.net/~bubbaf250/2150carb/carb02a.html
but it uses the "M" engine in the pics, but it should be similar to your Windsor.

Why? Is there something wrong with yours?

 

Is your carb a 2150? You could look here,
http://home.earthlink.net/~bubbaf250/2150carb/carb02a.html
but it uses the "M" engine in the pics, but it should be similar to your Windsor.

I think it is a 2100 but am not sure...how can you tell?

 

1973/74: The same basic 2V carb was used on Econolines & Bronco's with 302 engines, F100/350 302/360/390's and passenger cars with 302/351C/351W/400 engines.

The Ford 2V carb has a choke pull off diaphragm mounted on the air horn, under a cover with 3 screws. Just the goose neck arm is visible, it pokes through a hole in the cover. This diaphragm was first used in 1970. Earlier carbs don't have it.

The choke housing has a connector on the lower front where the hot air tube is attached.

Between the choke cover and the carb is the white plastic fast idle cam (it may have turned yellow by now).

This cam snaps in two after a few years, and may be part of the problem. C4AZ-9F577-B (Motorcraft CM-492)

Instead of a manual adjustable dashpot, this carb uses what Ford calls a Vacuum Brake Control. It's mounted on the drivers side adjacent to the linkage...it's essentially a vacuum controlled dashpot.

NOTE: The electric THROTTLE POSITIONER SENSOR is not used on this carb, it uses the Vacuum Brake Control mentioned above.

Look on the carb for the Ford triangular shaped Carb ID tag. It's mounted on the airhorn by one screw. If still there (it's usually missing by now), the coded number will tell exactly what the carb was original used on.

The Ford 2V was introduced in 1962, and many have been swapped around. The trucks 2V carb had a manual choke thru 1969, the cars had automatic chokes.

I have the 1973/79 Ford truck parts text and illustration catalog (on microfiche), this is where this info is coming from.

FTE member Mil1ion has this catalog on a CD and can scan and post a pic of the Ford 2V carb used 1973/74. The exact illustration is shown in: Illustration Section 95 / Page 4.

 

Look on the carb for the Ford triangular shaped Carb ID tag. It's mounted on the airhorn by one screw. If still there (it's usually missing by now), the coded number will tell exactly what the carb was original used on.

The Carb ID tag number is D3TF NA and A 2H 7 on the bottom
What does this all mean and does it tell me what type of carb 2100 or 2150?

Thanks

 

Welcome to FTE

That is the original correct Ford 2V carb for your truck.

D3TF-NA = D3UZ-9510-L > > REPLACED BY > > D4PZ-9510-AY .. Carburetor (Motorcraft CA-1795) / Ford parts catalog Carb Parts List # 29J
Original application: 1973 Econoline E100/300 & F100 302.

Carb Kit: D4AZ-9A586-A (Motorcraft CT-499-A)

Choke Pull Off Diaphragm: D0AZ-9J549-C (Motorcraft CK-1283)

Choke (plastic) Cover: D4TZ-9848-A Motorcraft CM-1809)

Choke Housing: D3UZ-9A575-A (Motorcraft CC-75)

Fast Idle Cam Lever: C4AZ-9F577-B (Motorcraft CM-492)

The parts catalog doesn't say whether it's a 2100 or 2150, only shop manuals have that info, but it IS the correct carb.

 

Thanks for the great help from everyone...I have been looking for this kind of help forever and now it looks like I wll soon be back driving the truck my grandfather originally owned...Where can I get my hands on a shop manual for this truck?
Also, what would be the correct way to set up my choke to see if that would help things out?
Thanks once again for all the help and the help and info in the future
TheBoys

 

Yes, The bi-metal choke coils have a habit of burning up and becoming useless

 

Original Ford Shop Manuals = faxonautolit.com / helminc.com

Mil1ion is the one to ask about electrical problems, vacuum diagrams, carb issues, etc. He's the FTE guru on these subjects.

I was a Ford partsman for 35 years, and can read and understand parts catalogs, but I'm not a mechanic.

Post #8, I added more part numbers for the usual parts that go bad on these carbs. Most autoparts stores can cross the Motorcraft p/n's over to the brands they sell.

 

Mil1ion is the one to ask about electrical problems, vacuum diagrams, carb issues, etc. He's the FTE guru on these subjects.
Mil1ion, I hear you are the one to talk to about this stuff......I am trying to set up my electric choke on a 73 F100 302...any pics/diagrams or general steps would help alot.
Thanks
TheBoys

 

Well for one thing the choke housing has to be indexed correctly for your application.

I don't have a chart for that year but I'll keep looking.

Until then, have a peek at this page and if you have any questions after going though it.I'll be around.

http://www.carburetor.ca/pdf_manuals...4Ford2100D.pdf

 

Thanks for the info Mil1ion, it gets me heading in the right direction...Maybe I should start at the begining of my problems. Last summer the truck ran good...the choke seemed to be working and all than one day this fall, I got in, stepped the pedal to the floor to set the choke and things did not work at all...it did not stay running unless I played with the pedal and when I came to a stop, she wanted to die out...Could the electric choke have just gave up and if I replace it things would be good again? Maybe this info could help.
Thanks again....your help is priceless...hard to find help with older trucks around here.
TheBoys

 

Well Like I stated before..Over time being heated and cooled the bi-metal coil fatigues then become useless

To confirm it works you have to test and retest under normal conditions.

The coil is ground through the metal area from the mounting screws so you would have to run a jumper wire to ground ...then with its power wire to stater terminal and using something to hold the spring coil in position have someone start the engine while you observe the coil pulling or pushing .... I forget which way it goes it has been so long since I did this.