OBD1ZC Swap

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Eighty-Nine Si

Eighty-Nine Si

Junior Member
Hi Folks, I’m new here! I have an OBD1 ZC that I intend to install in my OBD0 ’89 Honda Civic Si. I intend to convert the ZC to OBD0 but have heard different advice from everyone I have asked. I will be using my Si trans and ECU with a ZDYNE conversion. What am I facing?:confused:
 
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OBDI ZC=D15B VTEC? Are the spark plugs towards the header or intake manifold?

If it is indeed a D15B VTEC, just convert the car to OBDI and use a P28 ECU; and run Crome.
 
to install the OBD1 DOHC ZC in your car and run it OBD0 is pretty simple - you will need to swap the engine mount on the drivers side end of the block from your Si onto the ZC - you will need an OBD0 distributor - the best way to do it is to use the OBD0 DOHC ZC or 88-89 Integra distributor (they are the same) and install the 88-89 Integra CYLinder position sensor on the end of the exhaust camshaft - in order to wire it up correctly, you need to use your Si engine harness and do the wiring changes at the distributor for the OBD0 ZC - since you will be using your Si harness and your car already has an injector resistor box, it will be simpler to swap the OBD0 Si injectors onto the ZC rather than swapping the OBD1 ZC injector clips onto your harness and getting rid of the resistor box - you can do it either way, but swapping injectors is easier - you will need to extend the wires for the connector to the cooling fan switch, which is on the back of the block on the Si, to reach the cooling fan switch on the ZC, which is located on the thermostat housing - this will also require a different 2-wire connector, which you can get from the ZC harness - you will need to extend the wires for the connector to the MAP sensor, which is on the firewall on the Si, to reach the MAP sensor on the ZC, which is located on the top of the throttle body - eliminate the Si MAP on the firewall - your Si harness will have a connector left over which isn't used on the ZC - it is the connector for the Fast Idle Control Valve which is located on the back of the Si intake manifold on the driver's side end - you will need to swap the plug for the alternator from the ZC harness to the Si harness - you could use the Si alternator, but you would also need to swap the crank pulley as the OBD1 ZC uses a 4 rib alternator belt and the Si uses a 3 rib belt - you can download instructions for the Si to ZC distributor wiring here:

http://www.zcspeed.com/SiZCwiring.pdf
 
newbie

:mad: Whats up everybody just purchased an ef planning to throw LS swap. looking for something cheap. 94 ls
 
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