91 honda civic si

#1
i have a 91 honda civic si and the engine block is messed up so im thinking of doing an engine swap to a d15b vtec. what do i need to make this swap happen? i have never done a swap before so dont know what im doing to be honest but i am quick learner so please someone help me!!!:word::word::word:
 

jlicrx

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#2
If it is all stock, your Si is currently running as OBD0 – in order for VTEC to work correctly, you need to convert the car to run OBD1 - to convert the car to run OBD1, you need an OBD0 to OBD1 ECU jumper harness and an OBD1 P28 ECU or the JDM P08 ECU for the D15B - the OBD1 ECU has different wiring connectors from the OBD0 ECU which means you can't plug your OBD0 harness into the OBD1 ECU - the ECU jumper harness has connectors that allow you to plug your OBD0 harness connectors into the jumper and then plug the jumper connectors into the OBD1 ECU - you can purchase these jumper harnesses from a number of different places - i would recommend that you use the Boomslang jumper - this is the Boomslang jumper - if you order one just make sure you get the "MPFI OBD0 to OBD1" in the box in the center of the page and follow their instructions

http://www.boomslang.us/obd0to1.htm

there are a couple of other wiring changes that you will need to make in order to use the D15B engine - the D15B has the MAP sensor on top of the throttle body - your Si D16A6 used a firewall mounted MAP sensor - you need to extend the 3 wires for the MAP connector so that you can plug the connector into the MAP on the throttle body - the D15B has the cooling fan switch on the thermostat housing - the D16A6 has this switch on the back of the block next to the oil filter - you need to rob the connector from the D15B engine harness and install it on your engine harness so that you can plug it into the switch on the thermostat housing – you will need to remove the injector resistor box from the fuel injector system in order to use the fuel injectors that come with the D15B1 – the easiest way to do this is to connect the 4 yellow/black wires (1 from each injector) to the yellow/black wire that supplies the injector resistor box - you will also need a 4-wire O2 sensor

You will also need to remove the driver’s side engine mount from the end your D16A6 and install it on the end of the D15B – you can use your complete flywheel, clutch assembly from the D16A6 on the D15B
 






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