I just swapped a JDM D16A SOHC vtec motor from a 96-00 Civic fiero chassis EK5 or EK8 for a friends daily driver. The motor can be stamped as D16A or ZC from Japan. The motor was sold as equivelent to the Y8 in the 97 EX (the Y8 has spun bearings). Swap when well and the vtec solinoid, Y8 IM, and sensors were changed (timing belt water pump seals etc).

The problem is there is a loss of power between about 4500 and 5500 RPM. When the vtec kicks in at about 5500 and it runs strong again. The Y8 should kick vtec at 5500 so the car is acting correct.

I think the power loss is because the JDM D16A is cammed like a D16Z6 and the lobes expect vtec at 4800 whereas the ECU and Y8 maps expect 5500. This would explain the strange power loss in this range.

Does anyone have experience to confirm this is the case. If so, does anyone know if can I take the cam and rocker assembly from the removed Y8 and swap to the JDM head to solve the problem? What do folks do when they need a Y8 JDM replacement, is the D16A (ZC) SOHC vtec OK or not, if not do we have a beef with the importer?

Any help would be great.

 

new ECU

 

Thanks. ECU from what, the 97EX ECU in the car is OBD2a and maps to the 5500 vtec kick in. An ECU from a D16Z6 would be OBD1 so thats seems a poor solution. Do you know of a OBD2a ECU that will map to the 4800 vtec kick in?

Still thinking I should be able to swtich out the Y8 cam and rocker assembly rather than mess with the ECU. Anyone have information on the cam swap from a Y8 into this JDM D16A head?

 

Convert to OBD1

 

Thanks but no. Too much wiring and sensor change problems, besides the OBD1 would be illegal in the 97 anyway. I'm thinking the Y8 cam and rockers is the best bet and I'm hoping someone knows if they are drop into the existing head withod any modification. The competition cams for both the Z6 and Y8 are the same part, so Im hoping the cam swap is all I need.

 

It's already "illegal" regardless

 

No, I don't think putting a JDM ODB2 D16A SOHC VTEC from a 98 civic into a 97EX is illegal. My understanding is that you can put the same or newer engine in and be 50 state legal for emmissions. Maybe not... but anyway I am not going to OBD1 with an OBD2 engine and car. Thanks for the ideas though.

 

Wow I miss my JDM D16A. Have fun with that engine.

 

piggy back with a stand alone vtec controller? Or you could just buy a jumper harness from Skank2 get and obd1 computer and call it a day.