Re: You don't need "smart"...
Same car had this really odd problem where if the petrol tank was less than about a third full, the engine would cut out on left-hand bends.
A while back we had a car that was converted to run on LPG, with the option to switch back to petrol if you ran out. One day we had to run the LPG tank empty because a valve had to be replaced, and so we did. Driving, the engine dies just a few km from home (and the garage), and I flip the selector switch back to petrol. The engine stays dead. Coast to a stop. Check that, yes, there's petrol in the tank. Try to start again. Nope. Nada. Doornail territory. Call roadside assistance and get towed home. Figured out what the problem was: the tube internal to the tank sticking down into the petrol had dropped off its fitting, and the pump was just sucking vapours.
And the Vauxhall Viva that was my first car had a pinhole leak somewhere in a fuel line so that when you parked it with the tank filled over two-thirds, the excess petrol would find its way out. Filling up fully, then driving until you were down past the 2/3 mark: no problem.