gday have bee n running straight gas for a few years ..no problems..now the car is serging up hills as if starving of fuel..no problems on the flat..replaced leads ..plugs..aircleaner...clean solinoid...turned mixer one click to the richer mark and adjusted the idle screw...still has serging problems up hills..transmission kicks back....coughs and sputters..and feels like it is even missing..what next

Check for cracked or broken intake piping, or any other possible air leaks

start with replacing the gas filter at the lock off solenoid, what make of convertor.