Why does the RPM needle at 3000 on my 1994 Honda Accord start to shutter and the car will not go faster?

 

Most likely your engine is in limp mode. CEL lamp should be on. If not verify the lamp works. When initially turning the key to II(ON) the fuel pump should prime, the CEL lamp will come on for a few seconds(if AT the D4 lamp will also illuminate) and then turns off when the pump stops priming.
If it does illuminate, check for any stored codes. Two wire blue connector under the glove box door. Jumper it with a wire, turn ignition to II(ON) and watch the lights for blinking(codes).
If this is an EX 2.2 model, verify that the oil is full and that the pressure switch on the VTEC solenoid is not leaking.