1994 Mercury Sable Rough Start/run

MY 1994 MERCURY SABLE PUTTERS WHEN I START IT, THEN PUTTERS AS I DRIVE IT FOR SEVERAL HUNDRED FEET. I HAVE TO REALLY GIVE IT SOME GAS TO KEEP IT GOING, AT FIRST.

I'VE ASKED TWO MECHANICS AND THEY'VE TOLD ME EITHER NOTHING IS WRONG WITH IT, IT'S JUST OLD, BAD GAS, OR A BAD CAR. THESE ARE NOT SOLUTIONS!

IS THERE AN ADDITIVE I CAN TRY OR SOMETHING THAT I SHOULD HAVE LOOKED AT?

THANKS.:shakehead

Is the check engine light on? If so, get a free scan somewhere and post the codes here. If the CEL is not on, then maybe monitor the fuel pressure with a guage and see if it's not a fuel delivery problem like a fuel pump.