damesta

Did you ever figure this out? My r32 is doing the same thing, 16 flashes when I turn it on and feels like it’s stuck in 3rd gear limp mode, won’t downshift at all. No errors in diag mode, did a fresh fluid flush and it made no difference.

I'm sure it was an attempt to work around the stock a/c relay but it makes no sense because it is triggered from a signal that is coming directly from that relay....so if the stock relay didn't work this one wouldn't either. But anyway....I pulled it out and have been through all of the testing of the circuit per the fsm and everything checks out fine, there is nothing wrong with the wiring/signals or any of the a/c electrical stuff. However, my assumption that the system was empty was correct, so I can't fully test it until the rest of my parts get here and the conversion/recharge is done. The only reason I can think of for someone to do this is if the clutch wouldn't engage because of low pressure and someone assumed the relay wasn't working and tried to add another one.

True, just checked, makes no difference when its unplugged. I guess just I need to do the conversion and charge the system, I'm going to go through all of the testing in the manual but I'm not sure if there is a way to directly test the clutch engagement signal unless the system is pressurized and the pressure switch is working...so kind of hard to determine what the point of that extra relay was.

I haven't tried it unplugged, should the clutch engage if its unplugged? And I completely missed that in the r32 gtr manual, I was thinking it was just the engine section until I looked again. Thanks

As far as I know it is good, however, the new drier I will be installing comes with a new pressure switch so it will be replaced, that is the only pressure switch correct? Or are there 2 of them? What I'm really trying to figure out right now is why this relay was wired into the A/C clutch circuit. Does anyone have the actual a/c wiring diagram for an r32? All I can find is the eccs diagram which shows basic routing but it does not show the full a/c wiring details on it.

Yeah, I already ran through the diagnostics on the climate control, everything checks out ok, sensors and everything all work. But that diagnostic system doesn’t test the clutch, compressor or signal to it as far as I know. I’m really not trying to get it working right now, at this point I’m just trying to make sure it is wired correctly so I can start the r134 conversion.

Hey guys, so I'm starting to dig into my a/c problems on my r32 gts25. I am almost certain the system is empty and the compressor may or may not be good. I have ordered a new seal kit, fittings, expansion valve and drier to start converting it to r124a and fix whatever problems it has at the same time. So first things first, someone did some slight wiring modifications at some point and added this relay to engage the clutch. I'm not sure if this is just replacing a factory relay with a generic one, of if they actually added this relay to the circuit. But this is very much not factory wiring. They have the 12v power coming straight from the battery with an inline fuse and the signal wire to close the circuit and send power to the clutch is coming from the loom (a small blue/red stripe wire). The clutch will not engage when the A/C is on right now and I get no voltage reading on the blue/red stripe wire, however, this may be because there is no pressure in the system and the pressure switch is not sending a signal to it...but if I put 12v to the signal post on the relay then I can manually get the clutch to engage. So what should I do with this relay, completely remove it and return it to stock or use it as is? I know that the blue/red stripe wire originally went straight to the ac clutch single wire plug...so I’m not really sure what the point of installing this relay was to begin with. It does not allow the clutch to be manually engaged or anything like that, it still signals from the original wire and I cannot find any other modifications to the A/C wiring.

I already tested the voltage of the temp sensor and watched it as the engine warmed up, it was all within spec. I’m waiting on my consult cable to get here to be able to look at what the ecu is seeing though. I capped off the cold start valve, like the one you pictured, just to make sure it wasn’t stuck open letting extra air in, but it made no difference, it’s connected normally now.

I made a little bit of a discovery, I figured out that if I let the engine get completely warmed up (like I have to go drive for a little while warm...not just idle until its warmed up), then the idle will drop a few hundred rpm and when I unplug the iacv at that point it has no effect. We are still sitting around 1000 rpm though. Previously I had only been letting it idle until the gauge showed it was warmed up. I also checked the coolant temp sensor voltage and observed it as it warmed up and that was all within spec.

Alright, back to looking at getting a consult program set up then....greatly appreciative of all the info.

Hmmm, does anyone have picture of this flap so I can visualize it? I searched but don't see a flap anywhere on any skyline center plate pictures I could find. But yes, that is exactly what it feels like, would be bottom center of the plate, feels like I am lightly opening and closing a hinged flap with the wire, the closing making the taping noise when it makes contact....could be that I can only hear it because it is closing faster/harder due to the transmission being empty right now. Edit: Found a picture of an os giken gtr center plate with the flap intact, some of the other plate pictures I found of rb20/25 center don't have the flap intact but the hole for it looks lower and more centered than on the gtr box. I'm starting to think this is what I'm hitting, looks like it could move in and out a few mm and make a tap while there is no oil to cushion it.

Probably right....so here’s what I’m thinking. Since it shifts normally and I haven’t noticed any grinding or drivability issues maybe I can save this tranny. I think I’ll drop it out and pull the bell housing so hopefully I can get to the loose part and either remove it or fix it if it’s a clip or something. Then hopefully reassemble and reinstall.

I don't see anything but not the best angles, the area I'm talking about is pretty much right where the bellhousing meets the center plate on the very bottom...its just out of reach for me to touch with my finger through the drain hole but it moves very easily pushing it with a wire. Even if something was supposed to be loose like that in there it shouldn't be loose enough to tap something else and make a noise. Its crazy to me that this tranny shifts normally like this and hasn't torn itself up yet.

Thats what I figured, I have never opened one of these boxes up but I didn't think anything in there should be moving that easily. I was trying to explain as best I could but its not a loose fragment and is not freely bouncing around in there. It is still loosely attached to something (or possible sitting in an area tight enough to prevent it from moving anywhere), I can push on it with my wire lightly and move it up and down to make it do the taping noise, but I cannot freely move it around to where I can get it out.

Is there any reason not to just leave it idle at 1200 then? It’s a little high but if there’s nothing technically wrong I’ll live with it until I put a turbo on and get it tuned.

I have a rattle noise that I'm 90% sure is coming from the gearbox. It sounds like an inconsistent rattle of something hitting the housing on the inside, it is not a steady tap. The car shifts fine, no grinds or anything but I don't aggressively drive or shift hard/fast since I've noticed the rattle either. So I ordered some shockproof lightweight to see if that would help and I drained it today, the plug is full of the expected shavings but nothing big, and the oil looked relatively clean while draining. I have a little wire feeler that I stuck up through the drain hole to feel around for any debris and found nothing...but about 6-10 cm behind the drain hole I found something loose that I can make move by pushing on it with the wire feeler and I think I can hear it tapping the housing if I push it back and forth. It is not completely free, it won't move around where I can pull it out or anything but it is loose enough to easily move up and down to tap the the gearbox housing by just pushing it lightly with a piece of wire. Anyone know what this is? I assume it shouldn't be loose like that but I don't understand why it hasn't caused any drivability issues.....time for a new tranny or rebuild?

This also brings up the question in my head, is it possible that everything is working correctly and I'm just chasing a non-existent problem here? Is it possible that the combination of decreased load from the lack of a torque convertor and the auto ecu idling at 20 degrees advance is causing this whole issue and bumping the idle to 1200 rpm automatically?

So if I'm understanding correctly my base timing at the cas still needs to be set to 15 degrees at 650 rpm as the r33 fsm instructs? I'll get to searching for a decent consult. Thanks for the help.

So to clarify this, are you saying that if using an auto ecu then the base timing on a r32 rb25de should be set to 20 degrees at the cas and if using a manual ecu on the same engine the base timing should be set to 15 degrees? Or are you just saying they should both be set to 15 but that the auto ecu will automatically advance the timing to 20 degrees at idle? I don't have an r32 rb25de fsm but on the r33 engine manual I'm looking at it calls for 15 degrees base timing on both autos and manuals....could be different on an r32 though I suppose. When I say iacv I am talking about the complete idle air control valve assembly, mine looks identical to this ka24 valve with 2 solenoids, when I unplug the brown plug it will idle down and let me adjust the idle, when I plug it back in the idle jumps back up. https://www.z1motorsports.com/intake-mas-and-hoses/nissan/oem-ka24de-idle-air-control-valve-iacv-aac-p-9986.html?gclid=Cj0KCQjwkZiFBhD9ARIsAGxFX8AwwUSevaQlUXJexHhG1coTcwqGE_fxA7xLS8f_ahLOk6NUct43CmEaAr_3EALw_wcB I am not talking about the cold start valve but I did look at it already, I actually completely capped off the cold start valve at one point to test if air was getting past it causing the high idle but that made no difference either. And that's exactly what I was thinking, the ecu is trying to increase the idle speed for some reason but I have no idea why at this point....unless its a bad coolant temp sensor or base timing issue. Any recommendations on a good fully functioning consult cable/program to get started with?

Yeah, there was nothing but a little dirt in there. So the only two ideas I have left are to look at the coolant temp sensor and then maybe the timing, I've read somewhere that the base timing is 5 degrees different between auto and manual rb25's. This is a manual conversion running on an auto ecu, so maybe the ecu is looking for different base timing and trying to compensate? I need to research that idea a little more but it doesn't really seem like it would cause it to idle at 1200-1300 all the time.

What is a common cause, build up in the tb? Mine wasn’t that dirty but it made no difference when I cleaned it.

I don't have a consult to read the AAC duty cycle, I pulled the code from the ecu led. It did the same thing on both aac valves I tried though, so what does that idle spike when I plug it in mean? The other thing I haven't looked at is the coolant temp sensor, could the ecu bump the idle up if the sensor wasn't working and it thought the engine was cold?

Hey guys, so I'm working on a new to me 91' r32 gts25, mostly stock rb25de. I'm trying to sort out all the issues and get it reliable before any modifications. I have a high idle at 1200-1300 rpm that I can't get figured out. I have been through everything I can think of, checked every vacuum line/hose for leaks, cleaned mafs, cleaned throttle body, made sure throttle cable wasn't to tight and throttle body was fully closed, checked and adjusted tps voltage to spec, cleaned the iacv and then swapped a new iacv on. None of this makes a difference, even with the new iacv screw cranked all the way down the car idles at 1200rpm. I can unplug the brown plug on the iacv solenoid and get the idle adjusted down to a normal level at 800-900, but when I plug it back in the motor revs itself up to around 2500rpm and then settles back down to around 1200rpm. So it seems to me that the ecu is bumping the idle up for some reason. Trying to adjust the idle on the ecu has no effect either. I think this was an auto to manual conversion (although I wasn't informed of this prior to purchase) and it is running the BB ecu, the only code I can pull from it is 54, which means the ecu is not seeing the auto tranny signal from what I can gather....could this be the cause of the high idle? Thanks in advance for the help.