Dead Fuel Injector Connector

[300zx Enthusiast]

Ive been trying to solve the issue of my cylinder misfire/dead cylinder for awhile and finally narrowed it down to wire plug is bad leading into the injector itself. The wire is on the left side of the middle injector on the left side of the engine. I tried tracing it back, however i cant find the where all the fuel injector plugs lead together to form the harness for the injectors.

Essentially anyone that could help me through tracing the wire back, or just replacing the harness entirely for the fuel system as most of the plugs look bad I will greatly appreciate it.

TLDR; how do you replace the whole fuel injector wiring harness?

[NolimitZ32]

Its part of the EFi harness and leads back to the ECU, look at the link in my sig, the FSM has wiring diagrams.

[everpresentnoob]

yea, its not a seperate harness. it is tied and routed with the main harness. On some replacement harnesses like the painless one there i a connector so that you can swap them to the new style injector plug easily, but on a stoc harness the coils and injectors wires are bundled together and all are bundled and ran with the main harness into the cabin and to the ECU.

[300zx Enthusiast]

So given that all of my wires bundle together and lead back to the main ECU, how would you all recommend fixing my problem here? Ive been looking at some efi wiring harnesses but im assuming those arent going to be compatible given i have a stock harness?

[NolimitZ32]

You can either rerun wires from the ECU plug to the injectors separately of the harness loom, which is not ideal but if done properly will work without issue. Or you can buy a whole new EFI harness which is a huge PITA to change with the engine in the car but it can be done. I don;t think Nissan still produces these so you'd have to go with someone like wiring specialties. Last I checked the harnesses are around $400-500.

[itsa300zx]

Is there corrosion in the injectors wires themselves? If so how far does it go?

I would chase the wires back as far as possible ( maybe 6" from the connector or so) and solder in new injector connectors. Common procedure for most when upgrading injectors.

[300zx Enthusiast]

Is there corrosion in the injectors wires themselves? If so how far does it go?

I would chase the wires back as far as possible ( maybe 6" from the connector or so) and solder in new injector connectors. Common procedure for most when upgrading injectors.

Well weve found a few wires that look bad, but in all honestly every one of the injector plugs are corroded and bad which is why i bought a new EFI harness, which apparently is not compatible with my stock wiring harness?

[NolimitZ32]

You bought an injector harness, the EFI harness is the entire harness that runs from the ECU to everything. If you bought a new EFI harness than you just need to swap the whole thing out.

[300zx Enthusiast]

You bought an injector harness, the EFI harness is the entire harness that runs from the ECU to everything. If you bought a new EFI harness than you just need to swap the whole thing out.

So from what im interpreting it should just be plug and play with the harness that i bought? Or am I gonna have to resolder/reconnect all the wires together?

[NolimitZ32]

What you bought is a wiring specialties sub-harness that is made to work with their complete EFI harness, the OEM EFI harness doesn't have a location where the injector pigtails can be separated from the rest of the harness (no sub-harness) so if you were to change out just the pigtails and some length of wire on the OEM harness you would have to solder.

[itsa300zx]

300zx Enth. you are getting confused here.

Is this the EFI harness you bought?
https://conceptzperformance.com/nissan- ... p_8871.php

Or this Injector harness?
https://conceptzperformance.com/wiring- ... p_9421.php

[300zx Enthusiast]

300zx Enth. you are getting confused here.

Is this the EFI harness you bought?
https://conceptzperformance.com/nissan- ... p_8871.php

Or this Injector harness?
https://conceptzperformance.com/wiring- ... p_9421.php

My apologies i Did get confused somehow. I bought only the injector harness, what should I do with it then?

[NolimitZ32]

Sell it, or buy the rest of the EFI harness from Wiring Specialties and replace the whole thing, or put it on the shelf and forget about it, its not compatible with your OEM harness so in your current situation it doesn't really have any use unless you want to butcher it for the pigtails to replace the ones on your OEM harness.