RB25 wiring gurus needed please

[Paulpen]

Im quite a lurker, reader and searcher but less of a poster but hoping that wont matter :

Long story but here goes

18 months ago I did a RB25 (series 1) conversion into my S13. It was my daily at the time and I needed it to work so got someone to do it that was supposedly an expert at it.

I did the swap and it didnt start. No power to injectors or coils so I got it running.

Skip foward 18 months. Im now breaking my S13 and building a Onevia that the RB is going in. I cleaned all the unwanted wires from the car loom and then get to the engine one. Untape it etc and O.M.F.G its a mess.

Ive already sorted out the bodged pins in connectors but have a few questions that I cant really sort without looking at another loom or someone knowing it :bawling:

So here is what I know :

The R33 harness connects to the dash harness at one point so mine was repinned to fit my dash harness. Currently I have 4 wires in it which ive traced as follows :
Yellow/red - splits into two wires and goes to the tacho readout wire in the bay and the ecu
Yellow/green - to the ecu
Blue/black - Temperature gauge
Orange -> grey/red - ecu

And thats all I have in that connector as per pic
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00124.jpg


Im guessing this is the R33 version of what im using (but with more wires)
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00119.jpg
strange thing is that I have 3 wires going into this from the engine loom so they go nowhere !
Ive traced them so here goes

Black - goes to a purple inlent manifold plug - think its AAC (air con idle up) ?

Light blue - Goes to a gray connector with an orange insert, not sure where but possibly front of inlet area. Heres a pic or two as im crap with words
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00120.jpg
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00121.jpg

Blue/white - splits off into 4 wires after about a foot. These then go to a coil pack plug, what I think is the VVT (first pic below), the oxygen sensor and what I think is the boost solenoid (second pic below).
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00122.jpg
http://i20.photobucket.com/albums/b224/Paulpenuk/DSC00123.jpg.

If you are still reading then thankyou :)

The thing I find strange is that the car seemed to run fine on stock parts but did overfuel a bit and pulled 285ish on standard boost.

Help very much welcome ;)

[eh?]

check the rb25 diagram
RBforums - diagrams (http://rbforums.org/4.html)

[Paulpen]

I have been but not really sure where to start !

Traced every wire from the ecu connector to its end tonight and here is what ive now got. I used the following guide but not sure if its correct or my loom is missing alot of things :S

http://i20.photobucket.com/albums/b224/Paulpenuk/RB25Terminals.jpg

I made a table of what ive got and where it is and uploaded it here as cant seem to get the table to look correct any other way :(

MEGAUPLOAD - The leading online storage and file delivery service (http://www.megaupload.com/?d=1H3MZKDE)

[platez808]

hmm.. i looked at that table you made and its missing quite a bit.. dont know if you need everything though..

but if it's as messed up as you say it is, i would just start over with a brand new rb25 harness and a KA engine harness that you can grab the necessary plugs off of. You can do the conversion on your own and use the write ups online but i used the DVD to wire it and it really wasn't that bad, or pay someone again but make sure theyre legit (no offense to who did your harness before)

in terms of what you posted, off the dash plug the Y/R is the tach signal which should connect to Y/L on the ecu plug. Y/G is the speedometer signal coming from the speedo. That light blue wire, I believe, is the oil pressure gauge wire and should be connected to the oil pressure sender unit thing by the oil filter. It should be with a yellow wire (low oil pressure warning) at the plug by the sensor, too. Only thing is that the light blue wire is kinda useless unless you're using a cluster with stock oil pressure gauge or using an aftermarket oil press gauge. That's all i can remember off of the top of my head.

[Paulpen]

Thats cool ta for the input :)

I think im gonna get the engine loom back to stock and then convert it myself as then I can only blame me and its cheaper !

My main worry now is that the 2 relays by the ecu have been messed about with and I cant find the wiring for them anywhere

[GSXRJJordan]

I don't even know where to start with this... I do RB wiring (along with SR/1JZ/etc) often enough, and have just done a custom harness for my S1 RB25 - I know every wire/function. If you're trying to repair the harness to OEM-like, the FSM is readily available and has wire colors and diagrams that should help you do that... In my business, I am more concerned with getting the engine working with the least amount of wiring.

As far as the dash harness, it looks fine.

The white plug on the RB harness is not just a dash plug, it has all the power for the entire harness running through it, as well as wipers and a bunch of stuff you don't need.

The blue/white wire you were looking at, coming off the VTC solenoid, o2 sensor, and AAC valve, is Ignition-switched +12V.

That 6-pin connector is an upper/lower harness connector - the two wires wrapped in tape are your knock sensors, and I believe the gray/no stripe is injector +12V. I never have had the pleasure of having a complete RB25 lower harness, so I always wire the knock sensors to the upper harness directly, and power the injectors separately.

Again, I'm not quite sure why you're bothering with all this if the engine ran fine.

[Paulpen]

Although it seemed to run fine and pulled power surely it was not at its best with out 12v to the 02 sensor, VCT, AAC and the air regulator ?

Well after alot of time and help I think ive got it all done correctly now :)

Just a question about the coil pack loom though - is it meant to have 2 earth bolt connectors ? One goes the the white plug and one comes from inside the tape going to the pack connectors ?

http://i20.photobucket.com/albums/b224/Paulpenuk/Coilloom.jpg