rpm jumps after vtec engages

So i have a 90 integra with a b17 gsr swap with chipped p28 ecu and the rpm guage starts jumping around after vtec engages around 5000 rpm sometimes misfiring sometimes not and i just replaced the distributor and same thing im at a stand still on what it could be lmk fam

Wow with a chipped ECU… who knows. Can you do tuning or diagnostics sitting in the car? Who chipped it?

Is your timing belt on right? Where is your timing at… 16, 17, 18,… 25 lol?

I don’t know much about VTEC except that it affects the cams when it engages, weird the engine would surge and backfire though.