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wiring guide for installing a rb20det into a datsun Z


pat1

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wiring guide for installing a rb20det in to a datsun Z


I'm hope this will help some people wire up a rb20 into there datsun Z. The wiring is very easy and anybody can do it. If you have installed a radio,cd player in to any car YOU can do this.


First thing install the engine and run your wiring harness in to the cabin. Find a spot on the drivers side kick panel to mount the ecu. I have a 280z so I put the ecu in the stock location.



here is the pin out diagram for a rb20det.

 

FireShot Screen Capture #375 - 'RB20_ECU_Pinouts_jpg (800×459)' - wiki_r31skylineclub_com_images_9_9b_RB20_ECU_Pinouts.pdf

http://wiki.r31skylineclub.com/images/9/9b/RB20_ECU_Pinouts.jpg

study this and print it out.


Here is the wiring guide for the rb20

**Edit** Link Dead >   http://www.rbforums.org/pics/rb20.jpg

print this also you will need it.


Ok now it's time to get to work on the wiring.

On your rb20 loom you will find a connector thats on the same loom as the connector for the airflow meter. The connectors you are looking for is a two 8 pin connectors. One is blace and the other is gray.
On this connector you will find 3 wires that need power. 2 for the wires need constant power from the battery. They are a white wire with a purple tracer(W/P) and a white wire with a black tracer (W/BL) and the next wire will need a switched power. Meaning that it needs power with the ignition on that wire is Black with a red tracer(B/R).

You can find the constant power and the switched power off the wiring going to your ignition switch. This is easy to find using a test light or a DVOM meter.


Next you will need to wire up the fuel pump.

First thing you will need is a 30 amp relay

connect one side of the relay

using your ecu pin out print out I provided above

connect one side of the relay connector 86 to switched power(Meaning power with the key in the on position).
connect the other side relay connector 85 to wire from ecu terminal 18 which is the Black wire with purple tracer (B/P)
Now connect the relay connector 87 to the wire going to the fuel pump
and connect the relay connector 30 to a body ground


now with the key turned to the on position you should hear the fuel pump running

Now it's time to hook up your alternator,starter and reverse switch on the trans.

I used this page to convert my alternator to a internal voltage regulator.

 

FireShot Screen Capture #376 - 'Nissan_Datsun Z Car Voltage Regulator Conversion' - www_zcarcreations_com_howto_voltreg_htm.pdf

http://www.zcarcreations.com/howto/voltreg.htm

this is a very good write up on converting your alternator.

Hook up your stock reverse light wiring to the rb reverse switch.

I used the stock z speedo sender, I just swapped out the rb for the stock z speedo sender. I had to trim down the holder down abit with a grinder.

hook up the power cable to the starter and ground out your negitive battery cable to the block as it was on the stock Z engine.



Now for the gauges I used autometer gauges, Which is alot more relieable than the 30 plus year old z gauges.

I used this diagram to hook up my autometer tach to the rb

RB20_Tacho_Wiring-1.jpg





Now there are a few more wires that need to be hooked up and then you are done.

pin number 44 on the ecu is the neutral switch

there is two ways to hook this up. One way is just to ground it out or run a wire to the neutral switch on the trans. This wire tells the pcm thats is in neutral.

Now you need to hook up the start signal pin number 43 to the signal wire going to the starter solenoid this wire powers up the iac valve and the ecu tell the iac vale to idle up. This wire NEED to be hooked up or it will start like crap.
You can hook this wire to the back of the ignition switch Black wire with yellow tracer (B/Y)



Now with the ECU disconnected check all the powers and grounds at the ecu with a DVOM meter. And then you are done. This is easy.

Edited by RB26powered74zcar
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On your rb20 loom you will find a connector thats on the same loom as the connector for the airflow meter. The connectors you are looking for is a two 8 pin connectors. One is blace and the other is gray.

On this connector you will find 3 wires that need power. 2 for the wires need constant power from the battery. They are a white wire with a purple tracer(W/P) and a white wire with a black tracer (W/BL) and the next wire will need a switched power. Meaning that it needs power with the ignition on that wire is Black with a red tracer(B/R).

 

Next you will need to wire up the fuel pump.

 

First thing you will need is a 30 amp relay

 

connect one side of the relay

 

using your ecu pin out print out I provided above

 

connect one side of the relay connector 86 to switched power(Meaning power with the key in the on position).

connect the other side relay connector 85 to wire from ecu terminal 18 which is the Black wire with purple tracer (B/P)

Now connect the relay connector 87 to the wire going to the fuel pump

and connect the relay connector 30 to a body ground

 

 

now with the key turned to the on position you should hear the fuel pump running

 

 

+100 to appreciation, but I'm a little bit confused, could you provide pictures of the said steps? I've been sitting in my driveway scratching my head all afternoon, it took me a while to find the FP relay, and now I dont know what to do with it xD!

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+100 to appreciation, but I'm a little bit confused, could you provide pictures of the said steps? I've been sitting in my driveway scratching my head all afternoon, it took me a while to find the FP relay, and now I dont know what to do with it xD!

 

 

 

I wish I took pictures but I installed my rb last aug/sept and I didn't think about taking pictures. I did this write up from memory and sitting down one night and looking at the wiring diagram. I used a aftermarket 30 relay got at a parts store and ran new wiring to the fuel pump.

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I wish I took pictures but I installed my rb last aug/sept and I didn't think about taking pictures. I did this write up from memory and sitting down one night and looking at the wiring diagram. I used a aftermarket 30 relay got at a parts store and ran new wiring to the fuel pump.

 

Is it absolutely necessary to use a 30amp? What would happen if i used the current relay on my Z?

 

Edit: Also, did you use your stock engine bay fuse box or the RB20 fuse box?

Edited by WanganDevilZ
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You can use the stock fuse box and the stock fuel pump relay

 

After a bunch of knuckle bruising I think I may be getting it done correctly.

 

Edit: Still failing.

 

Then again I dont know if my ground is grounded.

 

I have the BLU/RED wire on my fuel pump relay (Fuel pump relay on ECU) connected to ECU terminal 18 (Labeled: Fuel pump relay) (BLK/PNK)

I also have WHT/BLK on my fuel pump relay connected to the WHT/BLK wire on my ignition, which should be ACC? What is wierd, is that my clock does not turn off. Even with the key removed from the ignition.

 

I also have wire 43 from the RB20 ECU which is ignition switch START signal, and i'm looking at wire 45, which is IGN Ignition switch.

 

Did i kind of do it right?

 

Think you could unscrew your kick panel and take a lookski?

Edited by WanganDevilZ
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lets start with pin number 43 which is the start signal. This wire needs a 12v signal only when starting. Behind your ign switch you will have the wire that goes to the start solenoid which gives a 12v power to starter when starting. My wire was black/yellow tracer (B/Y). Run a jumper from pin 43 to the B/Y wire. Your wire might be a different color. Do this grab a test light and check each wire on the ign switch. With the key turned to start find the wire that is 12v+ the run the jumper from the pin 43 to that wire and that part is done.

 

 

 

the pcm supplys the relay with a negitive signal from ecu pin 18,

 

connect one side of the relays coil wire to 12v +. Connect pin number 18 to the other side of the coil on the relay. On the contact side of the relay connect the wire going to the fuel pump and the other contact connector on the relay connect it to ground.

 

that should be it

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lets start with pin number 43 which is the start signal. This wire needs a 12v signal only when starting. Behind your ign switch you will have the wire that goes to the start solenoid which gives a 12v power to starter when starting. My wire was black/yellow tracer (B/Y). Run a jumper from pin 43 to the B/Y wire. Your wire might be a different color. Do this grab a test light and check each wire on the ign switch. With the key turned to start find the wire that is 12v+ the run the jumper from the pin 43 to that wire and that part is done.

 

 

 

the pcm supplys the relay with a negitive signal from ecu pin 18,

 

connect one side of the relays coil wire to 12v +. Connect pin number 18 to the other side of the coil on the relay. On the contact side of the relay connect the wire going to the fuel pump and the other contact connector on the relay connect it to ground.

 

that should be it

 

where are your grounds at? I'm having trouble finding them, and im sure that's my problem.

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  • 4 months later...



I know this is a late update, but its really my only day to be working on this with such a nice day outside, and it bein labor day and all, I thought it would be nice to give my Z a few hours labor.

The only "Connectors" i have, two are green, one is white, and one is gray/white

Pics y0!
W/P, W/B, W, Orange
090600_070300.jpg

First connector is on left. Right connector is B/W, W/B, W/B, and Orange, which is connected to the other connector
090600_070301.jpg

G/W, W/B, Orange, Cyan
090600_070400.jpg

Cyan, Cyan Red, Cyan Black, Orange, and Black
090600_070500.jpg


No 8 pin connectors like you described. D=

Edit: I found a gray connector that I had fail spliced a few months ago, it is a round gray connector with an orange inside, its colors are B/W, W, Black, and another black. I must have known something a few months ago because it was connected to my AFM, but it didnt look right...

Any help would be extraordinary!

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You will need to wire up the fuel pump.

 

First thing you will need is a 30 amp relay

 

connect one side of the relay

 

using your ecu pin out print out I provided above

 

connect one side of the relay connector 86 to switched power(Meaning power with the key in the on position).

connect the other side relay connector 85 to wire from ecu terminal 18 which is the Black wire with purple tracer (B/P)

Now connect the relay connector 87 to the wire going to the fuel pump

and connect the relay connector 30 to a body ground

 

 

The wires for the fuel pump are Bl/G, W/B, B, and another color. Now, there is a relay hooked up near the interior fuse box, and there is also one with identical wires near the fusible links box, except it has a yellow wire in addition.

 

Which one is which?

Edited by WanganDevilZ
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  • 1 month later...
  • 3 weeks later...

Thanks for writing this Pat1! I am piecing things together for the rb20det swap and this will prove exceedingly helpful. When my project really starts I'll be documenting it. Still waiting for the ARP head studs but have the Nissan gaskets and timing belt kit already. The motor will get a basic reseal because it's on the stand. The Thai Threddy intake arrived today so I'll be using that with a nice (ebay) front mount and stock turbo. A nice dump pipe should help spooling and response. The basic plan is bolt-ons that won't require special tuning. I'm going to see where the boost settles with the basic setup and see if I want to run a manual boost controller like a Hallman. Definitely getting excited for the swap

 

B)

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  • 6 months later...

I just got my rb20det running in my 280z. The fuel pump steps can be simplified by just splicing the fuel pump signal wire to the ign wire. This way when you turn your car on the fuel pump runs regardless. this also leaves room for a toggle switch if you so please. if anyone has any questions on the wiring just pm me and ill try and help.

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