Morris Minor Owners Club

Hi
Had a problem bring my 'new' convertible home in July, ran for twenty mile and then my wife and I towed the car the next 60 miles home.
Inspection indicated the fuel line was full of kinks, new fuel line fitted.
Inspection indicated the fuel pump wasn't right so exchanged for a known good one.
Inspection indicated the small tube to the carb jet was kinked, carb overhauled with new jet and needle and float level re-set.
Inspection indicated the tank was rusty inside, scoured out the tank, 'shaping' several small wired brushes to facilitate the job and pressure washed interior as best I could, ran petrol through and eventually when swilled around with petrol clean petrol went in and clean petrol came out.
Re-assembled tank to car.
This week the car went back on the road, and has now covered about 112 mile without a problem but yesterday it stalled with fuel starvation, fortunately a friendly driver stopped and help me push it the shortish distance home...(lucky I know).
Investigation started; disconnected the flexible line to the carb, turned on the ignition, no action from pump.
Broke the fuel line union to pump and the pump immediately starts to pump...admittedly air...but pumps...turned off the ignition.
Concluded, the line being new, that the tank filter must be blocked.
Tightened the union and, to prove I was right turned on the ignition, the pump unexpectedly fires up fills the carb and the car starts.
Leave the car running.....it runs but eventually stops again. The engine is by now hot. (by the way I think the thermostat is permanently open). If I tap the pump, it tries a pump or two but can't /won't keep running to fill the float chamber. I tap the float chamber thinking the needle might be sticking, no effect. (I had checked this when the carb was overhauled but you never know).
The pump is hot, the ignition coil is hotter, the fuel line to the pump is cool.
Where do I go now??? Anyone got any ideas...I'm stumped.

Try running the pump with the inlet connected to a container of fuel to eliminate possible blockage in the tank. It may be that the 'known good' pump is erratic...........they certainly can be when the points are on the way out.

I purchased a new fuel pump of the electro/mechanical standard variety direct from S.U. 5 years back, it had a breakdown (that involved hot electric internals) every 9 miles, once it was allowed to cool it was fine, for another 9 miles, I had it replaced and everything has been fine since.

Years ago, I had terrible trouble with the pump stopping on the old Traveller I had at the time. It gave me no end of trouble, but could normally be cajoled into life with a beating. I replaced the pump points, but it didn’t help - the pump still stopped periodically. So I saved up and bought a new pump, fitted it, and...... exactly the same. It transpired that all that was causing the trouble was a poor earth meaning the pump wasn’t getting the power it needed to run reliably. It would be worth a check on your car.

From the back...

No hole in the filler cap so the tank evenyually becomes a vacuum. Add hole or try without the seal?
Crud in the tank. wash it out or replace.
Tank internal pipe/filter blocked or broken. Hard to see. Crud gets stuck to the gauze or the pipe stem rots out.
Nipple into the tank leaks/splits. Soldered nipple can shear so that air gets in. Resolder.
Kinked/pinched copper fuel line.
Vapour lock due to pipe being cooked by the exhaust. Lots of options.
Filter on bottom of pump clogged. Undo brass nut and slip filet out.
Leaking valve in pump. Remove unions and clean out crud. Replace with service kit parts.
Torn diaphragm. Replace.
Rusted diaphragm shaft. Knackered.
Burnt out pump coil. Dead!
Points stuffed. Buy new ones or a new pump.
Dirty earth contact or power feed. Copper grease or Vaseline to keep corrosion away. New terminals or wiring.
Dodgy connection at fusebox. Green wires. Check for corrosion or dirty fuse.
Knackered fuel flexi. Can be killed by modern fuel. Check for splits or rotten goopy interior of hose.
Blocked valve in carb. 3 screws, lift lid and see if fuel can flow. careful of sparks and fires.
Sunken float. Brass ones crack after a while. Should be empty. Plastic ones also die.
Sedeiment in float chamber. Clean it out carefully.

...to the front.

Hope this helps. It should keep you busy for an hour or two!