85' F150 w/300: I did the DS II Conversion (carb, ignition, etc). Where is the electric choke "supposed" to be connected? Is it supposed to be getting a full 12 volts? Tks!!

 

Not if it is a factory carb and choke. The stocker is hooked to the stator wire on the alt. It should be a white with black stripe. it puts out 7.5 volts when the engine is running.

 

I did the DSII swap on my 85' w/300 6: So, I don't want a full 12 volts then??

 

That's correct.

 

It seems to run a lot stronger w/12 volts LOL

 

Edelbrock and some aftermarket carbs like 12volts to the choke. However, the factory carbs with chokes for Ford use the 7.5 volt stator connection. If you use 12 volts to it the choke will come off too fast and not warm the motor right. It could also lead to a short lived choke spring. Regardless after the motor is warm the heat from the engine compartment will keep the choke off. It shouldn't make a difference how the truck runs with 7.5 or 12 volts to the choke.

Where were you sourcing the 12 volts from? Are you sure it was only a key on 12 volts and not a constant 12 volts?

 

Its currently a constant 12. Its hooked-up to the starter relay.

 

Then you don't have any choke. That keeps the spring heated all the time so it never closes up or if it's on the cold side of the relay you are only getting voltage to it when the key is in the start position momentarily. If that's the case then the choke is staying wayyy tooo long and has probably fouled your plugs if you have driven it much.

 

I just unhooked the choke and plugged it into the wire coming of the alt w/7 volts and it wouldn't start.

 

Try disconnecting it from there and see if it starts - IOW with it hooked to nothing.

 

Something isn't right then.

 

Sounds like the carb isn't adjusted right. Maybe it's way too rich and the choke closing up is making it that much worse. If it will start with the choke completely off like it was then your mixture is off I would guess.

 

Well, I have Fri. and the weekend to figure it out. Prob. Just have to re-adjust the carb. Thanks for all the replies!!

 

A thermostatic "hot air" choke in conjunction with an electric assist is what Ford used on the stock Carter 1V carburetor and Motorcraft 2V carburetor. The way it works is this:

Clean, filtered air from the air cleaner is pulled through the "fresh air" tube (a rubber hose that is connected to the carburetor air horn and attaches to an aluminum tube) and into the bottom of the choke stove chamber on the exhaust manifold, where the air is heated up when the engine is running. From there, the heated air goes back up through the insulated "hot air" tube (attached on the top of the choke stove chamber on the exhaust manifold) that connects to the choke cap. As the air gets hot, it closes the spring in the choke cap, which allows the choke plate to open up as the engine warms up to run on a leaner mixture.




The "electric assist" portion of the stock choke system does not work on its own like an aftermarket electric choke. In fact, it doesn't have to work at all in order for the hot air choke to be effective. It is only there to "assist" the hot air choke in temperatures above 60 degrees, where it helps the choke come off sooner for cleaner emissions. It doesn't work at all when the weather is colder than 60 degrees. It connects from the spade on the choke cap by a wire that connects to the back of the alternator. This part of the choke is secondary, meaning the choke will work fine without it, but the choke will not work without the thermostatic "hot air" choke system.

You should be able to find a universal Choke Stove Kit,(Dorman 03840) in the Help! section of most auto parts stores. This simple, cheap kit (about $20) is designed to bypass the choke stove chamber on the exhaust manifold and replace the stock choke tubes completely. The kit comes with a length of coiled up aluminum tubing that you can easily bend by hand, the tubing insulation, the hardware to mount the tube to the choke cap, and a little "dome" with a hole in one end for the tubing to push into. This dome clamps to the exhaust manifold or header pipe to trap the hot air when the engine is running and routes the hot air up to the choke cap:



The stock thermostatic "hot air" chokes with electric assist works MUCH BETTER than the fully electric chokes found on all aftermarket carburetors in that the choke opening corresponds with the engine temperature. As a result, the engine gets the right amount of choke it needs, and because it uses hot air generated from the engine, it doesn't choke the engine when it isn't needed.

Capiche?

 

Fonzie - Well done. I rep'd you for that. But, I hope that is part of a sticky somewhere. If not it should be.