I got a b20 Vtec and it's a b16a head on it. The car starts up fine but when I try to rev it up it stumbles to go up in rpm and backfires and if I floor it it will just cut the car off. I checked the ignition timing on it and fixed that and made it where it don't do it as much but the car was sitting since august so could the gas be old? (that's what someone told me) or could it be that I am runnin a gsr ecu on a b16a head? Any help or anything would be great, thanks.