It's a 73' F-100 Custom with a 71' 351 Windsor under the hood project truck. The carb is the original Autolite 2bll carb on the motor. I recently replaced the fuel tank and sending unit. As well as Plugs, wires, dist cap, points, rotor and ignition coil. I also recently tore the heads off and replaced all the gaskets due to a blown head gasket on the drivers side (due to the previous owner not torquing the head properly). When I first drove the truck the 360 miles home after purchasing it on the interstate I was going an even speed of about 65-70 mph no problems ( even with the head not properly torqued). The Truck fires right up from a cold start every time. I live on an Army base so my driving speeds have been limited. The road with the top speed on post is 40 mph and I've had no problems driving the truck at that speed. So the other day I decided to take the truck off post to get some cruise time in. I got the truck up to around 50- 55 mph and she started sputtering on me, and after many attempts to give her gas and keep her going she finally stalled out on me. *Is it possible that too much air is getting into the carb?I've adjusted the idling screw over and over but, still the same issues. Also from standing to take off the truck chokes up a bit each time. I'm thinking my carb is bad but need an expert opinion.

 

Sounds like either the float height in the carburetor or the fuel pump volumetric flow is too low.

 

Sounds like fuel starvation, like fmc said check float and/or fuel pump.

 

Thanks for the feed back. My carb is the original Autolite 2100 2bll. It has an electric choke that isn't hooked up, it's just there. I'm guessing to check the float I'll have to pretty much take the carb off the intake and crack it open. If so would I be well off to go ahead and buy a rebuild kit, or would it just be a wise idea to buy a new carb like a Demon or Holley?

 

The cheapest route would be to simply rebuild what you've got, but neither of those options are necessary at this point. One nice thing about the Autolite is that you can remove the air horn and access the float without removing the carburetor from the intake.

 

Awesome, I'll have a crack at it and let you know my end result, thanks!

 

aye let us know please I got the same issue only on my 390

 

Check the point gap under the distributer.
Check for battery power at points when key is on.
check wiring going to coil and points.
replace points and condensor.
Consider going electronic ignition?

 

Yeah, I took the air horn assembly off and the float seems to be in one piece. I'm not to familiar with carbs it seems to be a science all it's own. There was plenty of fuel in the assembly and the float seemed to be functioning properly. I've got fire to the engine no problem. I turn the key and it's running in one crank. I just replaced my points condenser, coil, plugs, wires, cap after putting the heads back on due to the blown gasket. Seems to just choke out when I get around 50 mph. I don't smell gas, as to think it would be flooded by gas. So my only assumption is that too much air is choking it to stall. When it first starts to sputter around 50mph if I slow down and hold it say around 40 mph it evens back out and runs smooth.

 

Could the fuel pump work but possibly not supply the constant amount fuel to reach 50 mph or greater and hold it?

 

Do you have an electric or mechanical pump?

 

mechanical.

 

Check your fuel lines for blockage you could have a problem with restriced flow that was the problem with mine.

 

Ya know, when I first bought the truck it had the original fuel tank. When I replaced it, the old one was caked with rust inside. The sending unit was pretty horrible too. I had to change the fuel filters constantly until I got the the new tank installed. If I take the lines off will I easily be able to flush out any rust chunks in the lines? Or did you have a special way you cleaned yours?