MG Car Repair: Engine cuts out after a few miles of running., talladaga al, bright sun light

Question
I purchased the 1971 MGB from an individual in Talladaga, Al. and drove approximately 280 miles back to Mobile Al. Since we returned home it has not run but a couple of miles each time then wait an hour or so and then restart. I replaced plugs,wires,points,rotor,dist. cap and condenser but this didn't help.Any pointers would be appreciated.

Answer
Hi Earl,
You need to do some tests and the tests need to be done while it is in the failed mode.
All piston engines require the same thing to run, Compression, Fire & Fuel with conditions on each. Enough Compression, Good Fire (Spark) at the correct time & a combustible fuel available to the combustion chamber in roughly the correct air fuel ratio.
Compression usually will not come and go, so you can concentrate on Fire & Fuel. Fire can come and go and return again but is easy to test.
When the car quits remove a spark plug and put the wire back on the plug and lay the plug up on a metal part of the engine so you can watch for a spark. (Not out in the bright sun light)Then have someone spin the starter over for at least 5 or more revolutions and watch the spark. It spark should be blue in color and at least as thick as a pencels lead. I thin yellow or orange spark that is thin like a hair is no good and that is your problem and requires more testing in the ignition area.
If the spark looks a good blue thick spark put the plug back in and wire on the plug and continue on to fuel. where it is quiet turn the key on and listen for the fuel pump to start running in the right rear of the cockpit. If it is a SU pump or same type it will start clicking then the clicking will slow down and may stop or get very slow. It could have been replaced with a different type of pump and you may or may not hear it run.
Do this, take a spray can of either starter fluid or WD-40 or such and while someone spins the starter spray it into the intake. It is always advisable to keep a fire extinguisher handy when working with any kind of combustible fluid around a car.
If the car tries to start by running for a second or so, then you have a Fuel problem and further tests are required in the fuel area.
Run these two tests and let me know the results and I will give you the next step.
Howard