my friend swapped a d15b vtec into his 90 crx si, and it stutters at low rpms and smokes at high rpms. we have changed the ignitor, coil, cap, rotor, plugs, wires, tb gasket, intake mani gasket, eacv, fuel filter, o2 sensor. we have checked the timing a couple times and its good. we have also triple checked the wiring. im not really sure what else to try.

btw, its converted to obd1 and and has a p28 ecu. he also tried the p08 ecu and that didnt help either.

im not sure if we are just missing something obvious or what, if you guys can think of anything....that would be nice! if anyone here has done this swap or a z6 swap and has some pics of their dizzy wiring and vacuum lines, that would be helpful also. thanks in advance!