Stalling vehicle

what causes my 1993 Ford Ranger XL 4.0V6 to stall when hard braking/decellaration or accelaration. Professionally/competently tune-up/oil change/throttle body cleaned/fuel-injectors cleaned. Used correct spark plugs at tune-up the one specified for 4.0V6. This happens most frequently when fuel is low(qtr tank or less) but it does occur with plenty of gas. Changed idle air control valve and thermostat as advised by another mechanic but stalling still occurs. It starts right up and runs fine with the exception of the occassional interruption:). HELP Me

Check both ends of all the battery cables. Make sure they are tight and clean.