Partial Throttle problems

["Chris C" <petleech@xxxx>]

Before we replaced anything, we thought it could have been the 
pressures. The pressures on all injectors was the exact same, so we 
eliminated that problem. The car is a 5 speed manual, and we've 
checked all vaccuum lines including replacing the o ring on the 
vaccuum tube inside the manifold. Perhaps the fuel lines would be a 
good place to start, my father claims the fuel pump changes notes. 
The problem is most noticible in first gear,if I have accelerated and 
then take my foot off the gas, it feels like you were inside of a 
washing machine. Even at 1500 rpm though, the engine does not sound 
completely smooth. I will check the fuel line, as you said, and keep 
you posted.