i have 91 civic SI with a b18 LS motor..lately ive been having this problem where ill be in 3rd 4th or 5th and as soon as i give more gas ...it will bounce from 4,000 rpm and go up and down..and i can feel the car bogging...now wat kind of problem could this be?...injectors?...motor itself ?...anybody have any suggestions?...and it doesnt seem as fast as it use to be....

 

dirt injectors, but rmemeber, honda motors don't have any power in 4th and 5th gear unless your in a high rpm range say over 4000

 

based on the info you gave, sounds like you're having a misfire.

so yeah, check your ignition system aswell;
cap, rotor, plug wires, spark plugs (correct gap, and what not...).