I have a b18b1 currently in my eg civic. I am buying a rebuilt lsvtec motor, he is including the obd2 gsr wiring harness.

I am obd1. Id like to use my current ecu. What are my options, can I modify my current harness or do I have to use the obd2?

 

Get a jumper harness

 

So does that mean I have to use the obd II harness? or use the obd II ecu?

 

you use your obd1 harness, you use your obd1 distributor and swap any sensors that are obd2 on the new motor out for your current obd1 sensors.

Any obd2 motor can be obd1, its just a matter of using an obd1 harness, sensors, and distributor.

If your current obd1 LS distributor wont bolt up to the vtec head ( not sure on this) then you find a used obd1 vtec distributor.

 

So swap sensors, do i still need a jumper harness? What is the jumper harness?

 

no need for jumper harness, you are essentially going to turn that obd2 motor into an obd1 motor.

A jumper harness is used if the car/motor/harness is all obd2, and you want to run an obd1 ecu, the jumper plugs into the obd2 main harness allowing you to plug in an obd1 ecu, not needed in your situation.