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Rb25Det Engine Loom And Ecu Options

MODNIZD

By MODNIZD,
in Engines & Forced Induction

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MODNIZD Explorer

MODNIZD

Posted
Posted

Hi guys, hope I have put this in the correct section.

I have started a transplant of a RB25DET S2 Manual into my 1971 LC Holden Torana. I bought a complete crashed donner R33 Series 1 4 door with S2 Motor so I though I would have everything there but once I got it home relized that the guy had cut out the ECU. So I was left with a Engine to 100 wires loom and no ECU.

I have bought ECUs and 2 looms but both have not worked, and one didnt even have the white plug on it.

So now, wonder what other options I have? Should I just buy a aftermarket loom and ECU? Is that possible or will I still need a good R33 Engine to ECU Loom? I have 99% of it there but it has been cut 5cm from the ECU Plug.

The plans for the motor are mild, it has a FMIC, I plan on putting a high mount turbo manifold and front facing plenum to allow for space between the rails and decent exhaust but thats about it. I also plan on using the R33 Dash in the Torana.

I appreciate any info I can get. :)

Cheers.

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base308 Enthusiast

base308

Posted
Posted

S1 and s2 looms and ecus are different and not to well compatible in my experience has something to do with the coil pack wiring and setup if that's any help are you sure it's a series 2 motor because they look identical to an untrained eye hope that helps

Beer Baron Grand Master

Beer Baron

Posted
Posted

you can buy a short patch loom (call field extender or some such). it's used when people need to add stuff to their car that needs factory sensor signals but don't want to start hacking into their wiring. it basically has a female ECU plug on one end and the normal male plug on the other to extend the look a little. if you have everything but the ecu plug then I would buy one of those (about $100). cut off the female plug. then attach the wires to the ones now coming out of the male plug. the wiring diagram for the ecu connector is easy to find so that shouldn't be too hard.

they look like this:

H-111_500.jpg

MODNIZD Explorer

MODNIZD

Posted
  • Author
Posted

This might be a option. :)

I tired it with the Series 1 loom that I bought, cut off the plug and but had a few wires in the harness that had the same colour multiple times. Plus the series one loom has different colours and missing wires. Headache.

femno Grand Master

femno

Posted
Posted

Its fairly easy. Just find yourself a S2 loom, uncut, chuck it in, and there will be a few wires you need to power up for it to run.

Theres a grey plug on the P/S side which is power for injectors and coilpacks etc. Wire a couple up to power and thats done.

Then there will be 2 or 3 white plugs which require start signal and a few others to run.

It ll be tricky...Pinouts and wiring diagrams will help you.

If you want to run the 33 dash then thats going to be a bit (alot) of work. Just run a Monster tach or something for rpm! OR if youre really keen, transplant an entire R33 loom into the car! That will make things alot easier with wiring IMO.

If youre willing to do it yourself itll be alot cheaper than having an auto elect wire up a full standalone such as a WOLF or something else.

Youll also save on tuning if you can run a std ECU or even a PowerFC is alot easy to tune than a universal ECU and will run better.

MODNIZD Explorer

MODNIZD

Posted
  • Author
Posted

Cheers guys. Picked up a unmolested SII Loom tonight so will put that into the car on Thursday and see how it goes. Hope it starts.

I did thinking about transplanting whole loom, but I wont be running things like the A-LSD, Airbags, A/C so how will the ECU preform?

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Failing that you could have just grabbed a brand new one from Nissan.

They are actually rather cheap - around $600$-$700 if you can get someone to order trade.

Considering you've already brought 2 or 3 2nd hand ones so far, and all the fk assing around, would have been easier.

But as Femno said - just use as much of the loom as you can. It'll be much easier than using some of it and then wiring in another ECU entirely. That'll give you more headaches than you have already.

MODNIZD Explorer

MODNIZD

Posted
  • Author
Posted (edited)

Well the car its going into is super basic. No ECU's to be seen in 1971! So the extra wiring might be handy.

Plugged it all in last night and was left with some extra plugs (3 with decent gage wiring) up behind the rear of the pass side strut tower.

Plus a extra one down near the ECU. There is:

- Blue ECU Plug - PLUGGED IN

- 1 Relay - PLUGGED IN

- 1 White Plug (Which I think goes to the Dash) - PLUGGED IN

- 1 White Plug that is smaller than above - Nothing to plug it into?

I was guarantied that it is out of a SII R33 DET Man.

Part of me thinks its a SI Car with a S2 Motor in it. Any ideas? If that doesn't make sense can get pics up tonight.

Cheers for the help.

Edited by MODNIZD
DVS JEZ Grand Master

DVS JEZ

Posted
Posted

I think the one near passenger side strut tower is for the skyline wiper motor.

Have u tried to start it yet? Does the fuel pump prime Nd more to the point what fuel pump are u using and have u wired an ecu triggered relay for it?

MODNIZD Explorer

MODNIZD

Posted
  • Author
Posted

Nah I have that one plugged in.

So it turns over, I have Power on the Coils, Fuel Pump is running. What do I check next?

These are the unknown plugs.

It looks like the half of the plug below this photo, would plug into this on the left.

post-74735-0-90152700-1299150368_thumb.jpg

post-74735-0-28848700-1299150383_thumb.jpg

post-74735-0-99754400-1299150395_thumb.jpg

Don Dada Mentor

Don Dada

Posted
Posted (edited)

and here are the plugs near the wiper motor that I have no idea what they do.

post-74735-0-25622900-1299150814_thumb.jpg

Looks like plugs for abs unit

The other two plugs by the air box will most likely be for the boost solenoid and the ac compressor? (if its a single wire) maybe u can though up a pic of those as well....wouldnt affect the running even though

Edited by Don Dada

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