MGB starts runs well for 3 to 4 min and quits. Has fuel at the carbs, pump runs well fuel at carbs. Spraying starter fuel in the carb does not rev engine. After it quits turn the key it restarts but will not run. Wait a couple of min and restart it will again run well for 3to 4 min and quit.

hummm was the fuel filter changed? also check all the wires...sorry

I put a glass fuel filter just before the carbs (so I could confirm this (first of all trouble- shooting steps). If it's not being starved of gas (and) stalls all at once after warming up, you're describing electrical so I'd swap out the $5 condensor under the distributor cap, remove and inspect your sparkplugs for cracks in metal or ceramic and ensure all your plug/coil wires are well seated. Coils do fail but you have a new one; does it have the proper internal or external ballast? Cheers!