MG Car Repair: 73 MGB-GT stalling when warm, fuel pressure gauge, fuel delivery system

Question
My MG starts fine when cold.  Choke on.  After running a few miles and slowly pushing in the choke, it starts to act like it's not getting fuel or stalling.  I pull off the road and it will idle fine.  When I start out again, it runs afew hundred yards and does the same thing.  I assume it's fuel problem and not ignition/electrical?

Answer
Hi Keith,

It does sound like a fuel problem but the only way to be sure is to test. If it came to me with that problem I would put a "T" in the fuel line close to the carburetors and run a long hose out from under the hood and place a fuel pressure gauge under a wiper arm facing inside so you can monitor fuel pressure while driving. (be sure to put clamps on all hose connections)

Drive the car the same as when you have the problem and note the fuel pressure at the time of failure. Fuel pressure must stay from 1.5 PSI to 3 PSI at all times. This is a test of the fuel delivery system not the carburetors. If the pressure stays within range at the time of failure you should remove the tops of the float chambers and draw the fuel out to see if there is any water in the bottom of the float chamber. If you don't have any way to draw the fuel out just remove one of the carburetors and dump the fuel into a glass or pan to look for signs of water.

If all this is OK then you should take the carburetors apart and look for anything that can be restricting the fuel in the jets. (there is only one jet in each carburetor)

let me know,
Howard