Car cuts out

I recently rebuilt a 74 GT and all was going fine. I have installed a Weber down draft with electric choke. I drive the car 10-15 minutes and it's like I put my hand over the carb. The cars sputters coughs and quits. Pull of the road and it starts right back up again runs ok at low speed. Has new fuel pump, no vacuum leaks and carb tuned to run good.

Anyone had this problem?

Is your choke still closed when the car stalls? Sounds like it may not be opening.

Clifton

Yes you are right, I suspected the choke so I disabled it to stay open. Same thing! Runs down the road great then starts to cough spit and quits. Pull over starts right up and wants to go but only at very slow speed. I am switching my aim at the fuel pump. It is new with 3psi which should be enough to run a Weber or a wire is coming loose. You know how these things work, looking for a needle in a hay stack and it's right in front of your nose!

Is the tank venting properly? Remove the cap and see if that makes a difference.

Thanks Kim, thought that also. No luck.

I am leaning toward the fuel pump. Put on a Facet fuel pump with 3psi max. I'm told they run rich at idle and lean at speed which is what it is doing "no gas". I'm also told the Webers require 4psi to keep the max fuel in the bowl. Enter Moss, they have an electric with 4 psi.

Had another Facet from another car, put it on and ran the car at 1500-2000 rpm for some 15 minutes and no problem. Will replace fuel pump anyway. If that does not do it then it's the gas tank flow.

Any other suggestions I would appreciate them. Have never had this problem in all the years working on MGB's.

Thanks Kim, thought that also. No luck.

I am leaning toward the fuel pump. Put on a Facet fuel pump with 3psi max. I'm told they run rich at idle and lean at speed which is what it is doing "no gas". I'm also told the Webers require 4psi to keep the max fuel in the bowl. Enter Moss, they have an electric with 4 psi.

Had another Facet from another car, put it on and ran the car at 1500-2000 rpm for some 15 minutes and no problem. Will replace fuel pump anyway. If that does not do it then it's the gas tank flow.

Any other suggestions I would appreciate them. Have never had this problem in all the years working on MGB's.
Just in case all else fails, check the strainer on the end of the suction pipe in the tank. Over the years they can plug with rust and whatever. Also I've had a suction hose swell inside due to age and restricted the flow. PJ

I forgot to mention, A problem I had once, which was basically the same thing, as it would run for a while and then quit and then re start and go some more. The shielded suction line between the fuel pump and the tank had a crack in the hose hidden inside the braid and the pump was pulling a small amount of air along with the fuel. I replaced the line and it solved that problem.