Just swaped out the d16y5 in the 97 civic for and d16z6.
for some reason the only ecu that will run the motor without hesitation is the stock hx obd2 ecu... tried running 3 other obd1 ecu's and I end up with the same problem, the car hesitates till it finally reaches 4500 rpm then takes off... with the stock obd2 ecu the car runs ok till 5k then power instantly stops.
car is idling at 1500 rpm and SOMETIMES surges from 1k to 1500.

any ideas why this is happening?
I even tried running a p2p ecu and it acts the sames as all the other obd1 ecu's (P28, P06, chipped ecu's etc)

 

i got guts out of a y7 dizzy and put them in the z6 housing, tried running a stock ex ecu and a p28 . car runs but runs like ***. lots of hesitation. any ideas? already replaced plugs and wires, cap and roater.