First off I'm new to these forums so if I'm repeating others I apologize, not having any luck with the search feature. I've rebuilt and set this carb on top of my 351m and initially it idled great but after a few days it started to miss. Pulled plugs to find 3 out of the 8 to be bridged. Been a frustrating mess since. I'm missing the decal under the hood to tell me the settings for fast idle and all that. It's a stock motor with all the emissions junk. Could someone help me out with a good description/link on setting this carb. I'm thinking my hot air choke/fast idle are screwed up and I only am making it worse. The fast idle keeps coming back on when I start to accelerate so I know I got it messed up and need help with a good description on setting the coke/fast idle.
Thanks

 

Look here....

bubbaf250

 

Thanks for the quick response. I'm pretty sure my power valve went to pot this time.

 

Your fast idle cant "come back on" when you accelerate.

What readings are you getting on your vacuum gauge?

 

I'm pulling 17 pounds of vaacum as the carb is set right now. How many pounds vaacum should I set it for. Some say to adjust the idle mixture screws to get your highest vaacum reading so that is what I did. I replaced my hot air choke setup with an electric choke. My bimetal spring was weak. Seems to have a huge difference. Still is running rich, makes your eyes burn. Float level is 7/16 at the tip of the float, set to specs from rebuild kit.

 

What kind of "electric choke" did you get? Most factory-style "electric" chokes are electric-assist meaning they still depend on the hot-air stove to get hot enough for the electric portion to kick in. If it says Motorcraft and has a single tab, it's likely electric-assist. A factory electric-assist choke will not function properly in the absence of the hot-air stove. The factory setup consists of a hot-air stove with electric-assist choke. Acceptable, but less ideal alternatives consist of an aftermarket fully electric choke, or cable-driven manual choke. If your setup deviates from what I have described in any way, fix it.

You're looking for 18 to 20 inches of mercury (not pounds). 17 is close; I'm surprised it's that high if it's dumping as much fuel as you say. Fix the choke issue and verify that it's actually opening with the engine at temperature. Other than that, a leaking power valve (blown, leaking, or not seated) could cause that behavior.

Your next post should say: "I verified the choke is open at temperature," or "it's not, let me go fix that," or "help, I don't understand."

 

I swapped my new, leaking, power valve for the one that was previously installed and it fixed thee issue at hand. Replaced hot air choke spring and all seems to be working again. Thanks for everyone's input and help on this matter.