rb25det s2 in r32, now runs but a few small issues

[blackcomet]

hey, I just recently installed an rb25 s2 in an r32 using the r32 tranny, aftermarket plenum and front mount intercooler. Further I am using the rb25 harness and ECU. I just have a few issues, hopefully someone here can shed some light.

1) temp gauge doesn't seem to get a reading, I have heard of using the temp sensor from the r32(the skinny one near the top of the rad hose)..anybody else have this problem?

2)my wipers do not work, I read that I can use the rb25 plug and the only issue was that they do not turn off unless you splice the orange wire in the plug into the r32 body harness plug. However my wipers do not turn on at all. Any ideas?

3)finally I have rough idle and it bounces between 1000-2000rpm constantly, i thought it was a vacuum leak seeing I dont seem to get more then 10 psi on my vacuum gauge and I believe it should be more around 15-17 (correct me if i'm wrong). If not can it be a problem with the TPS or something like that?

thanks

[blackcomet]

anybody want to help a brother out here???

[collector240sx]

Hi,

Just did the top harness last week for the RB25 I'm putting in the girlfriends '95 240sx.

For a RB20 to RB25 it should be VERY easy IF YOU KEEP THE RB20 HARNESS, from what it looks like.
See instruction here : http://www.skylineowners.com/forum/s....php?p=1159280

But if you want to fix the above, I would strongly suggest you look at the F4\M64 plug below :



Here is a RB25 schematic http://www.gweeds.net/nismodore/rb25diagram.jpg (Nice picture, but to big to attach directly)

1) Find the blue wire with the black stripe and occasional grey dot, and find which plug it's suppose to go in your car.
Sorry don't have RB20 harness diagram, but if you have it post it here and we can have a look for you if needed.

2) The RB25 use the white plug showed above for the wipers, you can see this by the 2 ticker line in the schematic going to plug A35 and A36 on the top of the page.

I found that the wiring for the wiper section on the RB25 is the same as the S14 (JDM) with SR20 on the above plug.

From the picture below here is the wires for the wiper (they're all next to each other, on the big end)



Pink = Wiper washer switch
Green = Wiper motor ign 12V
Green\black = Wiper high speed signal
Green\red = Wiper low speed signal
Brown = Wiper off \ intermediate switch

Again don't have the RB20 wiring, so can't tell you where to connect them.

3) First thing, did you do ANY wiring, and what.

[blackcomet]

thanks for the reply, ya that has been the biggest problem the whole swap is finding proper r32 rb20 dash harness pinouts. There seems to be a good amount of rb25 diagrams and pinnouts, its just knowing where to connect it on the r32 side, ya I already used the rb25 harness. Had it been a series 1 i probably would of used rb20 harness but with the series 2 i prefered to use the rb25 harness....and yes i did the whole swap myself including wiring. like i said it runs but there are a couple small things not working...what would make a world of difference is knowing the pinnouts for the r32 rb20 dash plugs(the 3 or 4 plugs next to the ECU)

[ToroGTS]

Try unplugging the TPS with the engine running and see if that eradicates your issue. I have the issue of a idle bounce or constant surge and I whole heartedly believe it is TPS related or ECU hardward related to TPS output.

[blackcomet]

ya I am leaning towards TPS as well, however seeing I am using rb25 harness and ECU, I dont understand why it would be giving issues, the only thing I can't think of is because I swapped my intake for a plenum

[ToroGTS]

Nah it will be TPS voltage, idle contact signal, power supply, short or discontinuity in wiring or a ECU hardware issue related to TPS sensor circuit on the ECU board its self. Did you try running it unplugged? You may have to start the car with tps plugged in and then unplug after, sometimes wont start with no TPS.

[blackcomet]

small update, well it has actually been a while but the car now runs fine, figured out the small issues like the IAV and fuse box. Anyway seeing there is no complete write up for a series 2 rb25 into r32 anywhere, if anybody has any problems with this swap feel free to ask. I may actually do a full write up if I get the chance seeing none of the ones I google for series 2 are even close to complete. This would be for RB25 S2 engine with harness and rb25 S2 ecu into r32 gts-t.

[spinnanz]

small update, well it has actually been a while but the car now runs fine, figured out the small issues like the IAV and fuse box. Anyway seeing there is no complete write up for a series 2 rb25 into r32 anywhere, if anybody has any problems with this swap feel free to ask. I may actually do a full write up if I get the chance seeing none of the ones I google for series 2 are even close to complete. This would be for RB25 S2 engine with harness and rb25 S2 ecu into r32 gts-t.

Have done the same conversion into a 4wd cefiro. What we did was mod a rb20det loom a to fit the rb25det.

Main mod was changing the injector plug on the 20det loom. We then converted the rb25det engine which was orig s2 (no ignitor, different coils) to s1 rb25det throttle body, tps and coils. We left the CAS as s2(cant fit an s1 cas on s2 cams) but changed the plug to suit it on the rb20det loom. We then ran an extra wire from the ecu plug to the vct solinoid. A s1 rb25det ecu then plugged directly in.

Next on the list is to fit an rb25det neo engine, the s1 inlet manifold and electrics etc will all bolt onto the neo motor so no mods will be needed at all to get it running as such. Ecu will be swapped out for a z32 ecu which will then be re-mapped to suit the neo.

[blackcomet]

I was thinking of doing it the same way you just said, however from what I had read, I wouldn't of been able to run the vct solenoid...So you are a running an S1 ecu, is it stock?

[spinnanz]

the ecu we used was from a 1993-95 rb25det powered r33, these have vct. when we say "s1" over here it refers it to having come out of an s1 r33. these run the same afm/cas/tps/coils as the r32. they also run a coil ignitor, however it is differnt to the r32 one.

forgot to mention we also used the r32 ignitor and coil loom.

The ecu was stock, no need to change it as the later rb25det (has no coil ignitor, we refer to as "s2") is mechanically exactly the same as the "s1" with the exception of the key-way on the end of the exhaust cam, which is why we had to use the cas from the s2