My Struggles with and Unknown RB25DET Series 2

[s14owner95]

I picked up this motor, and was told it was from an R34. I didn't pay more for it than a standard RB25 S2 so I'm not upset about that, and it looks in better condition than most of the ones I looked for during my search. Well now, it's turned into a headache. I posted some stuff up in the RB FAQ section, but I realized I kept posting huge posts, so I figured maybe I could put up a thread that might turn into my "build thread"

Things that I have found out so far (I'll update this original thread as I go, maybe it will help someone else out)"

1. There are DEFINITELY newer version RB25DET that are NOT NEO motors. This motor has a metal turbine, side feed injectors, integrated ignitors and a CAS that looks just like an SR20DET
2. I was informed by the guys at NIStune that if you were to get an R34 NON-NEO motor, you could get a NEO ECU and get their Series 4 NIStune, otherwise, they don't support the standard ECU
3. The ECU wiring for the motor is the same as the R34 GTT (RB25 NEO)
4. If you want to get an R34 service manual google will turn up this link Nissan Skyline R34 Workshop Manual English (http://www.scribd.com/doc/5332929/Nissan-Skyline-R34-Workshop-Manual-English)
5. Forget the standard RB25DET wiper wiring, I am slowly figuring it out, and I will post up my progress as I go
6. (My favorite new knowledge so far)For those of you doing ANY swap (SR, LSx, RB, Jet Engine) if you want to keep your ABS, you can take out all the ABS connectors and you will be left with 5 wires, a black one, 3 green ones and a yellow one. These are a ground, TX, RX and CHK, and Tachometer, so all you need to do is splice into the new upper harness you have on those signals and you "SHOULD" (i'll confirm when mine is running) keep ABS
7. My RB25 is from a C35 and the ECU is P/N: 23740 5L801 and it's got "P3" stamped on it. (Verified with FAST, thanks Sileighty_85!) Although I do not know if this is for an A/T or M/T

[s14owner95]

(My KA blew up, and I was 80% ready to go back to an SR, but something in my head talked me into an RB25 (mainly because I lied to my wife and told her I could get away with it for cheap, somehow that convinced myself too, stupid stupid!)

Hey I know this is a huge post, but I didn't want to clutter the forums with another thread. I read through this whole RB FAQ section and it hasn't come up. Although, I could ask what spark plugs, oil filter or belts to use for the 800th time..

So I bought an RB25DET... supposedly out of an R34. Of course google R34 RB and all you return is NEO. This motor has a metal turbine, no secondary butterfly on the throttle body(that ugly solenoid), side feed injectors, a 4 row ECU (which I haven't got from the company yet), the plastic CAS, coil pack ignitor but a push type clutch...what the hell do I have? A hybrid? Also, doing the wiring I've found that I have a lot of connections on the ECU wiring that only goes to A/T stuff. *sigh*

I'm an avionics technician in the Navy, so I do wiring for a living, seems stupid to send off my stuff and waste my own talents. (But good luck finding an R34 Non-NEO wiring diagram, the google search "R34 scribd" returns the FSM for the R34, but the diagrams it shows always has the NEO version DET motor.

Question 1: So as it stands, I unpinned all my ABS stuff from my KA to try and make it work on the RB (since ABS is independent), but I'm stuck with 4 wires that go the ECU that I don't know what they are exactly, and if I need them in the RB harness (I know, ABS is for lames, but I figure what the hell, I'm already balls deep into this thing, I might as well do it, plus I don't have the money to delete it right now). There are 4 green wires, and one yellow and red (I know the black one is to a common ground). On the RB side, i only see one pin from the ECu that is a ATS/ECM/ABS combined ping. So anyone know how to finish this wiring off?

Question 2: Since the company hasn't sent my ECU, does anyone know what the ECU code is for my engine? I'm guessing it's an R34 non-neo?

Question 3: What the hell am I doing?

Question 4: (it's a long one, and I posted it down under in Skyline Australia)
I have searched 100's of Google Pics, looked for write ups from various people but I think I can only get the right answers from the people who actually OWN the cars.. So if you've got that information as well, I'd appreciate it. So here's where I'm at. I took some pictures to show my dilemma.
Here's a picture of my motor how I received it:
http://farm6.static.flickr.com/5065/5658988974_821d765e3c.jpg

I need to know what the connectors in RED go to (yes, I know one is a light, what light?) I figured out after I stepped away from the mess for a second, that the gray wire is for the ABS sensor on the front LEFT tire on a Skyline, so I'm going to evaluate the harness and see if I need to move it to read the front RIGHT of the 240sx
http://farm6.static.flickr.com/5102/5658415311_4f3e0866f6.jpg

Here's a close up of that bundle of wires, I know that they go right around the MAF:
http://farm6.static.flickr.com/5109/5658415591_852b85eeb6.jpg

I also need to know about the other half of the wires, the connectors on the right are under the dash, and the connectors at the top are in the engine bay, and most of the wires are contained in that bundle:
http://farm6.static.flickr.com/5308/5658415973_69cf93f90f.jpg

here's a close up of those connectors:
http://farm6.static.flickr.com/5183/5658990000_e2f0a9c3c2.jpg

I researched Yahoo Auctions Japan and found those two grey connectors go into this box, but one auction says they are an Auto Mission Computer and one says that it's an ABS Computer, it's under the dash:
http://farm6.static.flickr.com/5309/5658992492_2b63173074.jpg


:trogdor:

[s14owner95]

Of course, I forgot to mention that JWT also suggested my engine might be from a C35 laurel..

Also, I spoke to the guys at NIStune and they told me that if the ecu/connector is Gray then it is made by Hitachi (it also says Hitachi on the ECU's) and the blue is a JECS style (normal information I'm sure) but they were telling me that if you get an R34/C34/C35 engine like mine, but it's a non-NEO version, you can get an NEO Version ECU and use a NIStune on that, since they don't support the non-NEO version ECU.

I also made some progress on the wiring harness pics. The two gray and 1 white connector that are attached to a group of grounds and go to the engine bay are for the ABS system, so I removed that part. The blue connector goes to the "Turbo Pressure sensor" and the three wire gray connector goes to the "heated Oxygen Sensor" (I'm dumb for this one, since I pluged it in one.

But that one last big black connector, it's 8 pins. I traced all the wires, and it goes to various places:

Line Pressure Solenoid (A/T Only)
Line Pressure Dropping Resistor (A/T Only)
Control Unit Power Supply (Counter-Electromotive Current)
Control Unit Power Supply
The purple connector on the IACV
Air Conditioner

Do you guys know if these are input signals to the ECU? I obviously don't have the other end of that connector, and I can't seem to find the diagram in the FSM. (I should really just make a thread of my failure)

[usmcgetsome]

You have a RB25DET SERIES 2 MOTOR. I can confirm this by u sayin that the coil packs have igniters in them already. The series 1 RB25DET has a coil pack igniter. Hope that helps u. It shouldn't matter what chasis it's out of. As long as it was in a standard not automatic car. Also, your throttle position sensor is for an automatic which leads me to understand that it came from an automatic car.

[s14owner95]

Yeah, it's an automatic motor.. trying to figure out what to do with that whole TPS thing. i was going to go with a Q45 TB, so I think it should be fine.. (thanks for that note that the TPS says it's AUTO, never heard that, and it makes a lot of sense)

[fliprayzin240sx]

Thats what i was gonna say. Series 1 RB25 has a seperate igniter chip thats on top of the coilpack cover. Series 2 doesnt have an igniter chip as the function is built into the coilpacks themselves.

[s14owner95]

Yeah, I basically knew it was a Series 2.. I just don't know what chassis it came out of. The people who sold it to me say it's an R34, but JWT and other people with FAST capabilities say otherwise.. It's alright, it's RB25 Series 2, and I'm making it work

[s14owner95]

OK, so I have figured a few things out, and still got myself stuck at a stand-still. (At this point I don't know if I will get flagged, mainly because I read on a fairly well known website that anything that has to do with RB25 wiring is a "closely guarded trade secret" which I respect, but at the same time there are plenty of D.I.Yers that want to know so I think it's about time more information got out)

I took those RB25 F3 wiring swap information sheets and compiled them into on document for myself. I'm thinking that regardless of whether you are swapping an SR, RB, CA, LSx it shouldn't matter because ultimately with the plug you are trying to get the ECU harness (F3) side to match up with the body harness (M63) side and get the proper signals going to your gauges so everything works. The problem of course is that the ECU signals say different things on different pin outs and you have to learn each signal. I have an issue now with the fact I thought engine RPM was drawn from the injectors, but the Black/Red wire on #1 (F63) is for ignition, which goes to the injectors and power transistor on the KA. I suppose I can just go with the diagrams provided, but I just kinda want to know why I'm doing what I'm doing. I compiled my F3 diagram, but then I think I realized that I numbered mine backwards, either way not like people are reading this, but I'll confirm tomorrow (I got really frustrated tonite thinking that I had myself set up to do this wiring and then I ran into a road block)

http://farm3.static.flickr.com/2606/5717353395_f442145213.jpg

My biggest problem is that if there is a required pin (according to the diagrams, and you can see you are fairly close) then there would have been a pin on the original KA harness that went to a wire on the other side. There isn't.

On the KA F3 plug it goes like this:
1- ignition
3- rear defogger
5,6,7- wiper
10- goes to that big ass 8 pin connector that runs "inside the loop" of the DOHC KA intake manifold
11- fuel pump
15- power steering
16- A/C hand control unit

So as you can see, I will have multiple conflictions with the pinouts that are secretly floating around the net. What I can confirm is that I only had 3 wires going out of the F3 plug that went into the windshield washer connector(out of the first 16).

(man, it's late, I just realized that I unpinned my wiper amp and didn't mark where those wires went on the F63 plug, that's a lesson kids, don't do that)

Well I can say that I did do one thing right, so far.. I figured out how to disassemble the ABS harness. It's completely independent of the ECU, save for 5 wires, which are mentioned in the first post, but if you want to take them apart, here's how the connectors would look:(just be careful, use a jeweler's screwdriver and note that the smaller connector won't come apart anymore than what it shows there)

http://farm4.static.flickr.com/3555/5717919180_0a2504c23c_z.jpg

then, when you finally take apart your ABS stuff and removed your wiper amp harness, they look like this (ABS on the LEFT):

http://farm4.static.flickr.com/3239/5717918558_be96a44867_z.jpg

I updated the first post with any good information that I found