how many wires do i need to run to the ecu? and which ones? and how many do i need to ground?

im throwing a 2000 jdm b18c type r motor into a 96 cx civic hatchback and using a obd1 gsr ecu with a jumper harness

 

Very simple:
1. Run a single wire to the vtec solenoid pin on your ecu & to the vtec solenoid.
2. If your running a usdm ecu that looks for vtec pressure switch, run a single wire from the vtec pressure switch pin to the vtec solenoid wire coming out of the ecu.

Wiring diagrams can be found on http://www.phearable.net/tech

 

... Also to note, the GSR ecu is going to runny pretty $#itty on the B18C-R... I'd suggest having it socketed and tuned. When you have the map set up for your chip, you can disable the VTEC pressure switch since your JDM B18C doesn't have one. This will make it as simple as running a single wire from the VTEC solenoid to pin A4 on the OBD1 ECU...