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Hi All,

I will need to remove the Wiring Looms & ECU from a 8B soon to retrofit to a NA and having never done this am wondering if there is a kind trick to it?
I believe there is something like 3 separate sections to the loom, and once removing the dash it should become a little more obvious.

I have a couple of questions.
I assume the loom can be pulled through the firewall etc without cutting any connectors off, is this correct?
Also do you pull them from the inside out or from the engine bay into the car?

Any help much appreciated.

Thanks in advance!!

You have a fun job ahead of you Mark.

Dash needs to come out (this is for LHD but picks up most of the fun stuff):

http://mostlymiata.blogspot.com.au/2013 ... moval.html

You have the dash loom, the ECU loom and the engine loom. You will need ECU loom and engine loom as a minimum, together with the immobiliser, ECU, ignition key, and the ignition key sensor ring. The ECU loom and engine loom connect using a big blue connector on the right side of the steering column (from memory - it's been a while).

It will be an easier swap of you take the dash loom as well and use the nb8b cluster. However, this may cause you some interchange issues with things like the NA switch block, HVAC controls, etc... So the more NB8B stuff you swap in (HVAC, switch block/column, etc), the easier it gets - but it all takes time.

Yes, the engine loom will pull through the firewall without cutting connectors. You will find it easiest if you just pop the firewall wiring grommet out and pull it out with the loom.

Good luck, this will take a while it's a great swap though.

Dweezle wrote:Hi All,

I will need to remove the Wiring Looms & ECU from a 8B soon to retrofit to a NA and having never done this am wondering if there is a kind trick to it?
I believe there is something like 3 separate sections to the loom, and once removing the dash it should become a little more obvious.

I have a couple of questions.
I assume the loom can be pulled through the firewall etc without cutting any connectors off, is this correct?
Also do you pull them from the inside out or from the engine bay into the car?

Any help much appreciated.

Thanks in advance!!

Thanks a bunch.
Really appreciate it.

I will be pulling tbe engine and gearbox out on Friday which should then make it all a it easier to tackle the loom and bits.

I am running a E440d adaptronic currently on my B6 in my NA6 and am waiting on a reply from Adaptronic as to how difficult it will be to get the BP6D working correctly with the NA6 Harness.

I would almost like to replace it all with 8B wiring and just run stock ecu.

Will certainly help with your link to get the pesky wiring out and then figure it all out later on!!


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Running the Na6 loom will present a few issues, primarily with things like the coil pigtails and the alternator circuit. But if you swapped in your NA6 alternator and found a ribbed pulley for it (or used an NA8 alternator), ran a separate loom to the VVT solenoid, and spliced in the coils, etc, that would be fairly straightforward.

Trackspeed (Savington) on MT.net has a good write up on the process - do a search there, should t be too hard to find.


Chris

Here it is:

http://www.miataturbo.net/engine-perfor ... ht=Na6+VVT

Thanks sooo much! !!!

Really appreciate it.

That clears up alot.
The swap will likely happen after this years season finishes.

Now to figure out what gains if any are to be had if I run the standalone vs stock ecu on a unopened engine.

I believe a fair gain on the VVt is available with just Bolt ons, Exhaust/intake, Ecu ect...

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Pulled the engine and transmission out on friday.
Not a great day for it but it worked.





Ended up just cutting the loom with tin snips at the firewall and i will use the connectors etc from the severed loom to wire in things like vvt.

Then threw it all on the back of a ute and drove it home.
Avoiding showers on the way.



Now that it is all at home and on a engine stand it can get a freshen up with all new rubber bits.
Then hopefully after all the rounds finish up for the year drop her in with the new wiring and be ready for next year in a new class.

I am worried about pesky 1800cc hondas though.....


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I do believe Savington has also recommended (though I'm not sure if its in the Definitive VVT thread) that it is far easier to add the wiring you need to the existing NA wiring rather than try to swap over to the NB wiring... I'll search to see if I can find where he was talking about that.

Either way, this is all relevant to my interests!

With the Definitive thread though you'll probably work it all out pretty easy.

There it were what I was referring to!

I get the idea that your plan is to somehow splice the cut '01 harness into your factory harness at one point, using the VVT fusebox and 6-speed wiring. This is a terrible, terrible idea, and it will create a TON of unnecessary work. Don't do it that way, no matter how much you think it's a good idea, and no matter how much others have told you to do it that way.

The easiest way to swap a VVT motor into an early chassis is to use as much of the original engine wiring as possible, and then add the incorrect bits last. I've done 3 or 4 of them now, and this is the method that involves the least amount of wiring alterations.

The stuff that will remain the same:

• All of the starter and alternator wiring, as well as the OPG wiring (use a 94-97 1.8 alternator and the OPG sender that corresponds with your gauges)
• The injector and coolant temp sensor wiring. You should pull the +12v for the VVT solenoid from this harness - it's the easiest, closest +12v. Your old CLT sensors (for the ECU and gauges) will carry over to the new engine.
• The wiring for the TPS and IAC (the connectors are different, but the wiring itself is the same) (Note for 1.6 guys, you'll either not use the variable TPS or you'll need to move some stuff at your ECU connector to use the factory TPS wiring)

The stuff you'll add:

• The cam/crank wiring. The OEM CAS has a 4-wire connector - you have a +12v, a ground, a cam sensor wire, and a crank sensor wire. Feed +12v and Ground to both of the NB sensors, hook up the cam signal to the cam sensor, and the crank signal to the crank sensor. Easy-peasy.
• The VVT signal wire. Grab +12v from the injector harness and then run your own wire for the signal to the control solenoid. There is no polarity, so hook up the +12v to either pin.
• TPS and IAC pigtails. The IAC is easy, since there's no polarity, but you'll need to pay attention to which wire goes where on the TPS connector. Each car has slightly different wire colors so there's no color-by-numbers for this one. I will usually hook it up temporarily, confirm the TPS function, and then make the connections permanent.
• Coil wiring. If you have a 94-97 NA, this is pretty easy - just hook up the wires as you otherwise would, and then use your ECU to drive the tachometer. If you have a 90-93 NA, it's slightly more complicated, as you'll need to bypass the OEM ignitor before you hook up to the OEM wires. This assumes you're using the 2001+ coils - if you're doing LS coils or keeping your factory NA coils, then you don't have to touch the wiring here.

[...] In general the philosophy here is to keep your OEM wiring and sensors whenever possible, and just take bits and pieces from the 01+ harness as needed.

This is actually I think what you were going to do so carry on!

Thanks Slug_dub.

Yeah that is pretty much what i have planned.

I am just hoping when it comes time to do the swap that it all goes smoothly.

I hate wiring and might try to get some help with making the connection as solid as possible as i always worry it will cause issues.



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