96 gsr HELP

just change the distributor in my car i'm using an external coil an while driving home last night the car had this how should i say lost of power for a quick sec the rpm just had like a crazy jump up an then back down to normal i was in 3rd doin bout 2500rpm an when it happen it went to 3500 rpm an drop back i have been having this problem wit my gsr but before when the vtec kicked in the rpm guage would read crazy so i got a new distributor an that stop.. what u people think