car splutters at about 3,000 revs on hard acceleration

help please!!!
when i accelerate hard car splutters and will not go over about 3,000 revs before i have to change gear? but if i apply the accelerator slowly builds up speed any idea any help is much appreciated also the temp gauge doesn't seem to move far off the white shaded area?????????

fueling problem i'd say, do the usual filler neck/crud in tank checks. replace filter and finally try another fuel pump

cheers will check it out