should be reet, is what im using. unless gsf pump is crap, or yet more crud has come thru and got stuck in it. whats the L pipe between pump & tank like, its not kinked is it? is the outlet on the tank free of blockages and did you clear the tank out good n proper before fitting?
edit: oh and check the inlet side of pump, if it has a wee basket filter in take this out. had no end of trouble getting fuel to flow on mine and I had fitted this basket from another pump. was fine after i binned it.