not really sure what the problem is

[socal200913]

when i drive a car sometimes after like 20+ mins ill be pushing on the accelerator and right after it shifts it feels like gas stops getting fed for a second and then ill continue pressing down and the car wont really increase speed eventually it will rev up real quick and go. i dont think its the trans cause it shifts perfectly and i had it rebuilt last year. could it be the injectors or fuel pump?( its really hard to describe sorry if this isnt enough info)

 

[SpooledUp]

How hard are you on the gas? Maybe getting Knock Retard in the shift.