Rb25 into r31/vct wiring

[Liam2421]

Hey guys just wired in a 25 into my r31 the car runs and starts fine but am having trouble understanding how to wire up the vct/o2 my understanding is they are powered off the same wire, I’ve read elsewhere that one wire for the vct goes to ign 12v and the other to ecu pin113, hoping some can shed some light for me as there are only 2 conversion guides I can find but one is just a alteration of the other and isn’t any clearer to me, cheers

Edited March 16, 2024 by Liam2421
Spelling mistake

[GTSBoy]

Do you not have the R33 wiring diagram?

[Liam2421]

36 minutes ago, GTSBoy said:

Do you not have the R33 wiring diagram?

I have a copy of the ecu pinout as per this guide https://wiki.r31skylineclub.com/index.php/Wiring_an_RB25DET_into_an_R31

[TurboTapin]

22 minutes ago, Liam2421 said:

I have a copy of the ecu pinout as per this guide https://wiki.r31skylineclub.com/index.php/Wiring_an_RB25DET_into_an_R31

You should have the wiring diagram handy and not just the ecu pinout. VCT on an R33 is one wire to 12VDC (Originally from fuse #17 but any 12VDC will do) and other wire to pin 113 on ecu. VCT solenoid is not polarity sensitive. 

[GTSBoy]

58 minutes ago, Liam2421 said:

I have a copy of the ecu pinout as per this guide https://wiki.r31skylineclub.com/index.php/Wiring_an_RB25DET_into_an_R31

I posted the diagram as an attachment in a thread just the other day. Search to find ti.

[Liam2421]

On 17/3/2024 at 12:24 PM, TurboTapin said:

You should have the wiring diagram handy and not just the ecu pinout. VCT on an R33 is one wire to 12VDC (Originally from fuse #17 but any 12VDC will do) and other wire to pin 113 on ecu. VCT solenoid is not polarity sensitive. 

Ok I’ll try get my hands on one but perhaps you could tell me if it goes off the same wire as o2 sensor Hopefully can kill 2 birds with one stone if I just tap ignition and the pin 113 into that, thankyou for your help

[TurboTapin]

5 hours ago, Liam2421 said:

Ok I’ll try get my hands on one but perhaps you could tell me if it goes off the same wire as o2 sensor Hopefully can kill 2 birds with one stone if I just tap ignition and the pin 113 into that, thankyou for your help

Yes, it's the same 12VDC circuit that feeds the O2 sensor, AAC valve, Boost control solenoid, etc. 

[schalachi]

Hi. how can I know if my VCT is working or not?