what wiring changes are required to to make my d16y8 work in my 91 crx si?

 

You'll have to add VTEC pressure switch and VTEC solenoid wiring unless you are converting to OBD1 then you'll have use the Y8's distributor with an adaptor harness. For the injectors you'll have to remove the resistor box or you can keep the resistor box and use the A6's injectors. You'll also have to change the plug on the Y8's alternator to the A6's so it'll plug in correctly. The fan switch wiring will have to either be extended from the back of the block of the A6 to the Y8's thermostat housing or you can just move the sensor from the back of the A6's block to the back of the Y8's. Also if you stay OBD0 you can keep the one wire O2 but if you go OBD1 or OBD2 you'll have to wire in for the 4 wire O2 and use an ECU adaptor harness to use the OBD1/2 ECU. As far as vacuum lines you'll have to do either of the following things either plug the wall mounted MAP sensor plug into the throttle body sensor of the Y8 or use the wall mounted MAP sensor from your car and run a vacuum line from it to the Y8's intake manifold. Also the Y8 will have a knock sensor on the back of the block that you won't use unless you use the Y8's ECU but if you stay OBD0 or convert to OBD1 you won't need it plugged in. If I get bored one day I'll do a how to using honda service manual pictures to have a better understanding of how to do it.

 

i have the Y8 ECU and harness and everything for the swap i think, i would be super greatful if you would write up a how to, im asking a lot of people about this and im getting different answers, another thing i was wondering about is the mounts, im going to keep my si tranny so i dont have to worry about those but the one mount on the engine block, do i have to get an after market one or will the one i have on there now convert over?