1990 civic si ls vtec swap help

Daniel S

New Member
Hey guys I have been building an ls vtec for a bit now I am getting close to putting it in the car but cant wrap my brain around the wiring parts. I have an ob2 b18b1 block with a ob1 b16 head from a crx. my question is if I want to run a p28 obd1 vtec ecu what harness do I need to get? or can I just modify the stock one? any help is very appreciated.

Stay safe out there
 

jlicrx

Senior Member
Hey guys I have been building an ls vtec for a bit now I am getting close to putting it in the car but cant wrap my brain around the wiring parts. I have an ob2 b18b1 block with a ob1 b16 head from a crx. my question is if I want to run a p28 obd1 vtec ecu what harness do I need to get? or can I just modify the stock one? any help is very appreciated.

Stay safe out there
with any swap, you always use the engine harness that came in the car and modify it as required - you simply purchase an OBD0 to OBD1 ECU jumper which will have the wiring for VTEC built in - the jumper will connect your stock chassis harness to the OBD1 P28 ECU - you will need to modify the existing engine harness for the OBD1 distributor connectors and the cooling fan switch connector - your B18 will have the MAP sensor on top of the throttle body whereas the existing MAP is on the firewall - you will need to extend the wires on the chassis harness for the MAP so that the connector will reach the throttle body - if you are using OBD1 injectors, you will need to eliminate the injector resistor box - actually, pretty simple
 

jlicrx

Senior Member
you can also purchase a jumper for the distributor - makes it plug and play

you will also need a 4-wire O2 sensor
 
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