JDM/USDM engine harness

[nismo831]

so im swapping in a jdm vg30de into my z, just wondering if i can use the usdm engine harness or do i have to get a jdm harness???

[marty1mc]

You can use a USDM harness or a JDM harness, no difference. There are differences, however, depending on the year. 94+ harnesses have different injector connectors (preferable but requires new injectors) and CAS connector (CAS is different as well). TT harnesses are also different from NA.

My recommendation would be to get a NEW harness. Electrical issues are the #1 item that causes all the little issues with these motors. After many years, the harnesses become hard and brittle, connectors break.

[OMAR-Z32]

i also have he same question, i got a jdm motor with the jdm wireing. the wiring on my na is all cracked and all the connectors are broken, so iam wondering if i can use the jdm wireing with the jdm tt motor ta im planing to swap? isnt it differnt beacuse its right hand drive? or can i relocate my ecu or somthing?

[marty1mc]

^ Compare your harnesses. The length from the rubber grommet for the firewall to the first breakout should be the same. If so, you can use the JDM harness. I think they are on the Z.

Again, I would recommend a NEW harness for any installation. Electrical issues with old harnesses can drive you batty.

[OMAR-Z32]

new harness is expensive dude. but the jdm harness is in excellent condition so im going to try to use it

[marty1mc]

Yep, it is. The JDM harness, even if it's in good condition is anywhere from 12 to 20 yrs old. When I did my conversion, I put in a new EFI, Alternator and Battery harness. It was worth every penny.

At a minimum, I hope you are doing a 120k kit? If that's too expensive, then cancel the conversion...

[OMAR-Z32]

Yes i bought the 120k kit from z1 also ac condenser,and new clutch

[marty1mc]

Good, not trying to be condescending (my previous post looked that way to me when I just read it). But, there are so many things that you can straighten out before your motor goes in that will keep it reliable.

On the AC, have you found the TT tubing? They are different than the NA from the Condensor and compressor to the firewall.

Also, consider buying an upper plenum gasket and valve cover seals. The ideal thing is to also buy the grommets for the cover screws as well. These harden and lose their ability to keep pressure on the screws to keep them tight, resulting in leaks. I put a thin film of RTV on the valve cover gasket between the gasket and the head surface before I close it up. Then, if the screws loosen, the RTV keeps the surface sealed.

Additional upgrades that are worthwhile - Silicone hose for vacuum/boost lines. You can get bulk silicone hose from Hosetechnique.com and it is worth it. Rubber hose for boost lines feeding the solenoids, plenum, etc will get hard and brittle.