Editing Forums/Z31P/z31-performance-upgrade-forums engine-management/Building a New EFI-Harness

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|op_user=floridaZ
|op_date=2015-11-14 03:22:25
|post_count=9
|archive_url=/Z31performance_archive/forum/z31-performance-upgrade-forums/engine-management/25436-building-a-new-efi-harness.html
}}

'''floridaZ:''' <small>(2015-11-14 03:22:25)</small>

I searched a bit and didn't find much but dead ends, but I'm planning on building a new EFI harness for my 87 since the one on there is craptastic. Also, it doesn't run. I figure somebody has to have done SOMETHING along these lines since 2012, so if I'm missing something, please feel free to post it up. Failing that, I'll document my progress and solve my own problem.

Or I'll fuck it up, shelve it, fail to follow through, and be another dead end.

Or whatever.

Anyway, for the actual wiring I think the best starting point is wiring from DIYAutotune. At $48 for 10' it isn't the ''cheapest'' option, but it's color coded and labeled so for ease-of-use it doesn't seem like a bad idea. They also offer shielded wires that could be used for the MAF sensor. 10' might be enough to do the entire harness, depending on how creative I am with the MAF and relay wiring. I don't have any emissions, I'm thinking of relocating all the random EFI relays under the battery tray, and I will be running blow-through MAF so I should be able to make it work.

[http://www.diyautotune.com/catalog/megasquirt-3x-wiring-bundle-1039-long-p-452.html http://www.diyautotune.com/catalog/m…ong-p-452.html]

They also have this in 22ga.

[http://www.diyautotune.com/catalog/wire-single-core-shielded-20-gauge-1039-p-416.html http://www.diyautotune.com/catalog/w…039-p-416.html]

MAF Connector

[https://www.z1motorsports.com/body-electrical/wiring-connector-assy-repair-c-4_31_69.html?osCsid=htjka8s6s69mal51dq4sln4m26 https://www.z1motorsports.com/body-e…al51dq4sln4m26]

EFI harness comes out tomorrow, I'm going to take some measurements and clarify some stuff with DIY before I buy, then track down the rest of the connectors.

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'''ozzyrulez:''' <small>(2015-11-14 06:25:35)</small>

I think Mike P has redone stock harnesses.

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'''les_joey_paul:''' <small>(2015-11-14 12:29:13)</small>

I've cut off and soldered in new connectors on a few places in my harness. Definitely not a bad idea.

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'''88sinZ:''' <small>(2015-11-14 23:20:45)</small>

don't worry about color coding, just get a big ol' spool of 22g, print off the ECU pin out, and get the proper pin removal/crimpers

I'd highly suggest building it on a plywood sheet and confirm continuity/polarity at pin & plug before installing, as it will help prevent any mistakes and be much easier to correct

lindsey-walter.jpg

lindsey-walter.jpg

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'''Augustus Maximus:''' <small>(2015-11-15 23:32:51)</small>

Or I'll sell you a pretty harness from an 87

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'''bdleonard:''' <small>(2015-11-18 01:49:37)</small>

If you're lucky (your model matches their stock) you can get a brand new surplus harness for about $200 shipped.

[http://www.oem-surplus.com/nwp/300zx-2.htm http://www.oem-surplus.com/nwp/300zx-2.htm]

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'''Augustus Maximus:''' <small>(2015-11-18 06:25:39)</small>

I think the po wants to build an harness from scratch. What I did do with one of my Z was unwrap the thing and cut out all unused connectors and associated wires all the way to where they started, then retube and wrap it for a leaner meaner look.

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'''floridaZ:''' <small>(2015-11-22 05:57:03)</small>

Oh, me and OEM Surplus are buddies now. They don't have an EFI harness. They have the engine bay harness, which is sitting in my closet all pretty and freshly dust/water-proofed. But not the EFI harness. If they had one, I would buy it and be done, since I hate doing wiring.

88sinZ, I considered that, and it is the cheapest way. But if something in the harness goes fucky down the road… I'd rather do it right once and save myself the headache of having to pull the harness later.

Augustus, define "pretty." I might be interested. I mean, I'm still gonna build this one, since a "new" used harness is simply delaying the inevitable for a few years. But I'm far from being in a good situation for my Z to not be running. So if it's in really good condition, fuck it I'm interested.

Ninja edit: While the shit's in the mail, what details would you guys like to see documented? There's no real supplier of new harnesses, so for those of us who plan to keep our Zs for like evers, this could be an eventuality. And if I've gotta go through the asspain of building a harness, somebody should benefit from it.

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'''ajaxism:''' <small>(2015-12-08 01:50:49)</small>

Something I've also considered doing.

You could document the following:

what gauge wire (easy)

bought new or existing pins?

crimped or soldered existing pins - how? (probably crimped them) Did it require a special tool?

re-used existing connectors? where did you get them from - another car?

what you've wrapped the wires in? there's self sticking tape vulcanized tape that you could perhaps use. quite expensive for that.

anything you've deleted.

any tests you performed (continuity, resistance, MAF wire)