RB25 Swap into a31 cefiro (rb20) and hicas delete Help.

[RHDskyline]

So my buddy and I are swapping in a RB25DET into his a31 cefiro. We just pulled the RB20DET out last night.

We will be using the RB20 tranny, so no driveshaft or sensor issues here.

We also would like to keep the a/c for the car as well. The Rb25 and the rb20 both are complete, as they both have ac compressor and power steering pump. RB20 is HICAS pump, rb25 is non hicas pump.

What would be the easiest AC compressor to use? will we need to get custom lines made up either way?

And since he has a hicas delete bar. What is the easiest way of doing this? Use the non hicas pump and cap/loop the hicas lines, or what?

I know everything will bolt up, so all thats left is the wiring. Ive been reading online and im getting different views on how to do the wiring.

The best ive come up with is this one.


We will be using the RB20 harness, as its 100x easier, and has no downsides.

You will need:

-Complete RB20 harness including injector sub harness
-RB25 injector sub harness.
- (optional) a plug that will fit onto the VVT solenoid, and some wire.

1) Take the injector sub harness off the RB25. This is the one with the plugs for the sidefeed injectors.

2) Cut all the plugs off, leaving enough wire to solder them onto the rb20 harness.

3) cut off all the top feed plugs on the RB20 harness. 3 are on the sub harness, and 3 are on the main harness.

4) Solder the sidefeed injector plugs onto the RB20 harness and sub harness.

5) You must swap the wires for injectors 4 & 6. Doing this at the ECU is the easiest Just cut pin 112 & 114 and cross them and resolder.

If you have an afermarket ecu (such as in the case of this install), and you can configure your outputs, you can do this in software. In our case we used an AEM EMS... its nice because it supports the RB20, 25, and 26 with one unit.

6) If you want your VVT to work, you must get a hold of the right connector for the VVT solenoid. If you have an rb25 harness, thats easy just take it from there, if not take a trip up to the wreakers and snag one off some random nissan that will work.

Then just solder 2 wires to it, plug it into the solenoid, and wire it up into the ecu. We didnt hook it up, so i'm not sure on the exact wiring. I do know pin 113 is a trigger for the VVT. It would be easy to figure out with a wiring schematic. If you need help with this, post a schematic that includes the VVT solenoid on it, and i'll tell you how to wire it.

7) Your done. Make sure you use an RB25 ecu or calibration.



That seems like a legit way to do it. Can we do it that way?


So we are wondering about the

HICAS delete
A/C
Wiring


Any help is greatly appreciated.


Thanks.

Nathan

[drader]

Use the hicas lockout bar and the non hicas pump and pull all the hicas lines out of the car, or just loop them if you want.

[RHDskyline]

how about the lines on the rack. There was 2 going to rear of car and 2 coming from hicas pump. Can we just cap those off at the rack.


any input?

[RHDskyline]

wiring does not apply to a cefiro. are they different rb20's ? because none of the plugs line up. looks like just keeping the 25 harness will be the way to

[DanShirts]

Take some pictures. My a31 needs a new motor too. I would like to see how yours turns out.

[RHDskyline]

well we got the engine in. and it runs. following a crazy wiring guide done by allen peterson.

but it works

[poledrift]

The lines are just folded at the front for the HICAS in my Cefiro, not the safest method. Im gonna loop the lines at the front

[supersayianjim]

pics


pics


pics!!!