is there any difference between the parts...friend swaped in my 93 h22a1 into his 94 si car...if you hit the trottle hard it stumbles badley at low rpm....but increasing throttle slowly there is no problem....plus it runs fine up top....are there differences in the years, or VTEC changeovers.....Thanks

 

Check your timing (ignition, then cam). Also check plugs/cap/rotor/clean injectors

 

did it all....