OK so let me give you a run down. My 1st car was a 67 Fairlane when I turned 16. Loved that car but one morning the streering knuckle broke at about 80mph. Needless to say it did'nt end well for the car. I have finally been able to get back to my love of older Fords after 20yrs. Now I have a 79 F-100 with the 300 inline 6. I test drove it and it was idled a little high but once in gear ran fine. While on the test drive ran out of gas( note to self always check if gas gauage works). We finally return the truck back to the guys yard and he was nice enough to knock $250 off the price for the no gas test drive. I went back the next day and bought it.
Here is where the problem began, it seemed to be overloading with fuel. Now I'm not a mech. but I do have a little walkin around sense so I started with the fuel filters. They blow thru with ease so I moved on to the carb. Pulled the top off to check for trash in the bowl, none. replaced all vacuum lines, new pcv valve, new air filter, new wires, plugs cap, rotor, and coil. Looking tomorrow in the light to get the number off the carb for a rebuid kit. After all this the problem has'nt changed, it still bucks and lopes in idle and puts out black smoke. When I give it gas it picks up good but once it levels off it starts to buck a little. Sorry for the long rant its just been a long day being the closest zone is about 30miles. Any help is thanked in advance.

 

Sounds like the floats are out of adjustment. You should be able to take care of that during the rebuild.

 

Ok time for an update. I rebuilt the carb(first ever). And not to toot my own horn but I am rather proud of it. Anyway, it helped, now i just have to get the AF mix right. It idles just a touch high but when up put it in gear it gets low. Almost to the point of stalling. Is there something I'm missing. During the rebuild I found alot of small trash in the bowl. Plus once I went to reinstall it on the motor I notice the space gasket was letting air by in 2 small spots. Would this be enough to mess with the idle?

 

Check your timing... sounds like it's set too low. Once you bump it up , you'll have to set the idle back down, but then things should be gravy.

Josh

 

You need to replace the gasket too.

Josh