What all wires must be ran to wire in vtec?
Car: 93 Cx
Motor: 98 GSR
ECU: OBD1 P72


So far I have done:

vtec solenoid -- A4
vtec oil pressure sensor -- D6
knock sensor -- D3
secondary intake solenoid (IAB) -- A17
evap purge solenoid -- A20

o2 wiring (I'm using a GSR cat. / plugging one of the o2's):

O2 Sensor Input - WHT to D14 (needs to be a shielded wire)
Heater Control - BLK to A6
Sensor Ground - GRN to D22
Sensor Voltage - BLK to A25 or B1

Is this right for the o2 wiring? I haven't done it yet. What would be the difference in using A25 or B1? Which one am I suppose to use?

BTW >> The civic o2 is also a 4 wire if it means anything:



This is the GSR's o2 (one of them):



Thanks for any help you guys can offer!

 

Yep sounds right. B1 and A25 are both switched 12V. Use one for o2 sensor power and use the other for secondary butterfly power, or just run the secondary buterfly power wire to the IACV power wire.

 

Wait if the civic harness already is setup for a four wire then just extend the plug to the teg motors o2 sensor, no need to make a mess at the ecu.

 

Is there anyway to find out where these 4 wires plug into the Cx shock tower harnesses w/o unwrapping the tape / loom?

I do have a Helms manual for both the 98 GSR and 93 Civic.

I'm dropping the motor off at some junkyard in a day or so. I'm just going to pull all the harnesses / wires.......

Still any help would be highly appreciated!
Thanks!

 

use a multimeter and run continuity tests.
Basically the white wire is primary signal
grn/wht wire is sensor ground
blk/yel is power
orn/red??? is heater signal

If the stock harness has a four wire o2 sensor plug then just extend it. If it has the 1 wire plug it will probably be easier to just wire at the ecu.

 

I pulled the entire Cx harness from the motor including the o2. I've got to get a lot of tape and wire loom off the wires, even though I already pulled a lot off.

The 4 wires from the o2 (shown in the pic above) should run all the way back to the end of one (or more) the harnesses that connect to the shock tower harnesses, right?

If this is true then I just have to find the pins at the shock tower harnesses and tap in at the shock tower.

I just want to get all this cleared up before I start running more wires.....

Thanks again!

I'll post pics of the harnesses (mainly o2) once I get it unwrapped and laid out. I have to get going to work now, but am off tommorrow