This is a standard design fault with the starion - the fuel pressure regulator doesnt shut quick enough upon demand. feels worse when idling for a while (sat at lights etc) then sudden accelleration away. this causes the injectors to open (there bloody big volume injectors) & suddenly theres a loss of fuel whilst the pressure regulator shuts to allow pressure to be sent to the injectors.
try fitting a FSE Fuel pressure regulator.
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=FSEPBV37230
additionally, replace the fuel filter as you can garantee the one on your car is the original from 20 years ago full of 20 years worth of crap & causing a blockage in the fuelline.