Hey guys giving as much info as I can here so hopefully someone can help as I need this fixed asap.

The car was running perfect, I took it to garage to buy some chocolate haha and left car running outside. When I went to pull away I got to around 4000 revs and it started missing. I changed coil as my mate thought maybe that was screwed under load to no avail. The car seems to tickover a bit lumpy now but revs out fine on spot. It does seem to be a bit smokey due to too much fuel? I have noticed that when turning ignition on the fuel pump doesnt sound as healthy as it used to. used to give a loud buzz now it a sort of drone sound could this be problem? I thought it may be giving enough fuel and not returning it fast enough hence the fuel smell from exhaust on idle, but up the revs the pressure isnt enough or not giving enough fuel? I honestly dont know. Plugs, leads, rotor arm and dist cap all replaced recently so aint problem there this why I think its to do with fuel any suggestions would be really appreciated!!!