46 ford misfire

[Deuce Man]

My 46 ford flathead v8 has a faint misfire at 40 to 50 miles an hour obviously this is at a very low throttle setting. The misfire goes away if I pull the choke out about one third. My motor is quite sound, has a Bubba's distributor, a Charlie NY carburetor and fuel pump, fresh plugs and wires, I even had Charlie down here in Florida go thru my carb He said " I hate going thru a carburetor like this" I asked why? he said" I couldn't find anything wrong with it" I am sure I don't 'have a vacuum leak as it idles like a kitten. I even have an electric fuel pump in line, makes no difference whether it is on or off still sounds like the motor is running too lean at cruise speed. I would run with the partial choke setting but when I stop for a light or something I have to push the choke in or it idles at a couple thousand or so! I am out of ideas, any help from you guys will be greatly appreciated, Thanks Rich by the way the motor is completely stock

 

[TomO]

It sounds like you have a restricted fuel line or a vacuum leak on the input to the fuel pump. Try replacing the flex line to the fuel pump. Use a correct flex line, not a rubber hose with clamps. Your electric fuel pump could be restricting fuel flow also.

 

[Norris McCarty]

I’d replace the condenser 1st. Cheap and easy. Sounds like a similar situation I had some years ago.

 

[Deuce Man]

Norris, just did that a few weeks , thanks

 

[G.M.]

Try some Marvel Mystery oil. Down the carb and
in the tank. Sticky valves. G.M.

 

[Deuce Man]

Tom O I am going to try running my car off a temporary tank, maybe one of my boat tanks. Take the tank, inline fuel pump lines etc. out of the loop. thanks for the idea.

 

[GB SISSON]

Had a very similar situation a couple months ago. Chased it for months. Mine went like this... It finaly broke down 5 miles from home. Got towed. the rotor had shorted to ground. Replaced it, but it still had the miss. The miss continued to worsen. I found one cylinder wasn't firing, and sometimes two. I discovered my plug wires that I had taken off a scrap motor years before were of the carbon type. Not real wire. I run 12 v and a bosch super coil. I bought a set of universal copper wires and made them up. My woodie has never run as well as it does today. Of course during the investigation I had tuned, adjusted and tweaked every system in the process, but in my case the problem was the bad wires.