TheOrangeSkittle

April 19

I tested them all a couple times, haven't tested it warm or wet though. The only seemingly really weird thing was the cylinders plug closest to the dash was pitch black nearly. Doesn't smoke out of the exhaust or anything.

Also sorry everyone for the very late response. Got busy with work and all and didn't get around to fooling with the car for awhile.

But an update! I figured out the cause of the lean condition, my intercooler had at some point exploded or something. It's clearly separated in a spot with black oily buildup around the leak, and multiple leaks in various vacuum lines. I've replaced it and the vacuum lines, and gotten new clamps and there are 0 leaks now after doing a couple smoke tests.

The car now runs significantly better and the exhaust doesn't overheat anymore. I still have the main problem though where the engine feels like I'm lugging it around sub 3500rpm in any gear besides 1st, 2nd It's less noticeable but 3rd anything under 3.5k and I need to downshift or the engine is clearly struggling when trying to accelerate at all, 4th is the exact same, sub 3.5k engine won't accelerate and its hard to bring it back up to speed, 5th gear doesn't feel like the car is going to straight up fall apart now but it still can't pull 5th. It slowly loses speed and rpm and ANY gas I give I can feel the shakes from the engine and it slowly dying. If I ever so lightly give it gas it will slowly and nicely decel till around 2k rpm instead of lugging. But it cannot accelerate at all or maintain speed.

If I go from first gear at 5 or 6krpm and then shift to second it also feels like it's struggling to make power till above 3krpm if trying to accelerate but I can cruise around parking lots at around 1-2krpm just fine in 2nd. It's just when accelerating hard it and changing gear you really notice it die down. But even if you shift at way lower rpms it does the same thing till somewhere above 3k.

As far as I'm aware it's got r32 gtr transmission gear ratios with gts4 diffs.

The tire size is 205/55r16 91h

Above 3500rpm the car pulls and runs and drives quite normally and the power from engine sounds and feels very smooth. It's perfectly driveable at above 3.5krpm but I drive on the highway alot for work and it gets really bad gas mileage in 4th at 4.4krpm. Not that I'm looking for great gas mileage with such a car, just I'm sure being at around 3krpm would be significantly better for it.

Have appreciated all your guys help. I do understand the engine may just be f**ked from running with a boost leak though.

One final thing I'd like to add is I'm only shifting so high in the rpm range is because if I don't I will feel the engine lugging bad with 0 power in lower rpms, pretty much anytime off boost trying to accelerate it feels really bad. Also when I say 3500 rpm I don't mean exactly. Just around there.

March 3

On 2/28/2024 at 5:55 AM, morboost said:

what sizes tyres (tires) do you have on it

I checked the compression finally. And while COLD with the throttle wide open, unplugged the CAS and took out all the spark plugs,

#1 125PSI

#2 123PSI

#3 107PSI

#4 120PSI

#5 127PSI

#6 104PSI

So I figure that's not too good is it? Judging from what I've read online for an rb20det.

As for the tires I'll have to check sometime, kept them the same size though as when I got the car.

February 27

On 2/23/2024 at 3:30 AM, morboost said:

A stock manual rb20det r32 in good condition should feel as quick as a fox body 5.0 not a corolla. Sounds like you car makes no power, pull the cat - is it blocked is the turbine wheel in it, rev the engine with the cat off is it making turbo noises, if thats all good, check the intake pipes try and find the rag left in it check them all intercooler, turbo inlet, airbox no rags - all good. Check fuel side replace fuel filter - all good, Now its time to do a leak down test and compression test, this is where you enter the pain of rb ownership welcome to the fu*king show.

It makes all the turbo noises and what not. Was going to just get new splitfire coils if the compression is good. It's got all the old heat cycled parts still on it. And was gunna do a leak down test. Like I said it makes no bad noises at all and sounds very smooth. Runs smooth. Boost comes on and it pulls but I suppose it's not pulling as much as it could. It completely falls on its face in fifth but after redoing that vacuum line to the fpr it significantly improved and doesn't totally die but now just feels like it's fighting a losing battle to maintain speed. I didn't see anything on the plugs except they had white on them. One plug looked completely normal though. I was considering if the compression is good (waiting till I get the harness so I can do a cold and warm test) doing the smart coil conversion and eliminate the ignitor, since it seems it'd be about the same price if I ever had to replace the ignitor for any reason and if I'm already getting new coils.

February 20

2 hours ago, MBS206 said:

Your motor felt fine though didn't it?
Water on the floor isn't a feeling

Well It's the only rb I've had and only turbocharged engine I've had. I don't really have anything to compare it to. Ran and felt fine before so I figured the 5th thing was just a weird kink due to the gtr box since there's few discussions regarding the gts4 and converting it and anu issues after. I did pull the plugs, and none are melted but they all have a white haze to them except one. I assume that being the effects of them being lean. The 1 looked normal and had a blackish brown bottom. But all of its on hold now since one of my igniton coil plugs just.. ehhh fell apart into like 30 pieces after plugging it back in and gotta wait to get a new harness for it, I know they're old and brittle but I barely even touched the thing. I've yet to get a boroscope.

I do appreciate your guys advice I'm just kinda a big noob to all this sorry.

February 19

On 2/17/2024 at 8:41 PM, MBS206 said:

And ran it super rich at idle, so dumping fuel out the exhaust most likely.

Lean under boost on the highway for 10+ mins... No wonder the exhaust heat and CEL came on... Likely was detonating badly, plus running super hot...

Wouldn't you notice if it was doing that though? It didn't sputter or make any bad sounds. Sounded perfectly smooth just oddly felt like it was lacking power. Past 4k.

February 14

26 minutes ago, joshuaho96 said:

I have a feeling you may have damaged the cat if you still have one. Pull the downpipe/front pipe off and make sure it's not blocked. FPR induced lean-out is not good.

Also, pull the plugs and make sure they're in good shape. Borescope the cylinders if you have one. Compression test the engine.

Well I only drove it two or 3 times likes that if I recall correctly. I was getting together a big sort of maintenence package together. With new plugs and coils and filters. So all that stuff I know when it was last changed. And getting a compression tester and such.

February 12

So an update for anyone curious or future people with similar problem, found a couple vacuum lines pretty cracked and leaking, notably the one on the FPR. I replaced them and the cars issue idling at start has vanished and seems to idle much better and return to idle much smoother, previously it'd drop to 600rpm sometimes and settle at 1k eventually. Now it consistently settles at 1k. Drives smoother and pulls harder and smoother with boost on, and seems like it doesnt struggle as much past 3krpm pulling the higher gears though it does still like being around 3.5k-4k rpm. Will need to get on the highway sometime to test it.

Some of these lines had came off while swapping the trans and I put them back on but due to age they must be working their way back off.

February 11

1 hour ago, CowsWithGuns said:

Sounds like you have engine issues. Compression and/or leakdown test would be my first call (either gain peace of mind or rip the bandaid off) followed by fuel pressure check, vacuum leak check to get your basics covered. IDK where you're at with tools but I've had great luck with ebay fuel and comp testers, and my ebay leakdown went straight to the bin.

Assuming your starting issues are related to the power issue, I wouldn't expect the exhaust to be a (major) concern as if it was really blocked you'd be flatlining power early and it would be fairly obvious. Nothings impossible though!

Yes I was probably going to try and install the new fuel filter I have already and see if that makes any difference, just been putting it off because I'm sure 30+yr old hoses are gunna be fun to get off in an awkward position. Sometimes it will literally start then idle at below 100 rpm unless u tap the gas for a split second then it jumps up to 1k and is fine. It's weird it does this in 5th only really, it will pull pretty strongly in 1st and 2nd then 3rd only if you're already past 3.5k rpm and 4th if you're past 4k rpm. Any lower in those and it'll struggle for a second then the boost kicks in and it's fine all the way to the limiter. I figured the exhaust was just from essentially being at peak boost for extended periods of time. I never noticed it doing anything like this with the autobox though and nothing else changed besides the transmission.

Thanks guys for your advice. After driving it I was thinking maybe vacuum leak or fuel issue or something. I hope it's nothing like compression, I've been pretty easy on the engine but no clue how the previous owner in Japan treated it. Maybe these issues were just masked by the torque converter.

February 11

Hello everyone, sorry for the slow responses. I had a chance to drive it on the highway again and I realized I've missremembered what the actual problem is.

Okay so there are a couple things going on, not sure if they're related.

So to start, whenever the car starts it starts up just fine but will die immediately unless you give it a blip of gas. It did this before when it was an auto still, and it only recently developed the problem before doing the swap.

It runs through all the gears smoothly, it doesn't like being below 3.5k rpm 3rd and up though.

To drive on the highway without 5th I need to cruise in 4th gear at about 70-75mph 4.2k rpms, but doing this for 20 or 30minutes eventually the exhaust/cel light lights up and I let off the gas and after about 10 seconds it goes away and doesn't come back. At least not for quite awhile.

5th gear is smooth and there is no issue with it but I can't maintain speed in 5th, if I accelerate to 140kph and throw it in 5th it'll slowly die down and lose speed/rpms, and the engine will begin to lug. If I try and give it gas at all, alot or a little at like 3 or 4k rpm in 5th the engine just lugs hard and is clearly struggling and slowly dies down till I need to downshift. It cannot pull in 5th no matter what without wanting to stall or slowly losing speed. I could probably get it to maintain speed but I'd have to be going something silly like 90 or 100mph down the highway.

Hopefully that's more clear on what's going on. Apologies for the misunderstanding.

February 8

15 hours ago, r32-25t said:

Do the auto gts4 have the same diff ratio as the manuals?

I think so? They have a shorter one than the gtr.

February 7

20 hours ago, GTSBoy said:

Well, just going by your description, it is the engine that is struggling. The struggle could originate in the engine, meaning that it is weak (weaker than it should be) in all gears and only becomes exposed by the tall gearing of 5th.

I had suspected this could be a thing too, but it is a relatively low mile engine. Only 80k miles on it. And I can understand the it struggling abit more and needing to be in boost to pull 4th. 5th just outright killing it seems abit much. But I don't understand gearing or ratios enough but I'm pretty sure the rb20det makes half the torque at 4-5k rpm than an rb26dett does. I may rebuild the transmission and swap the engine for rb25det in the future, I wanted to anyways. I can definitely feel the car struggling when it's not in boost to pull anything past 2nd, 3rd under 3k if you try and accelerate it just won't. It'll shudder and crawl upto 3.5k where it's no problem suddenly.

February 6

1 hour ago, GTSBoy said:

Just be aware that this might not be caused by the box. It might be clutch/flywheel balance issues, or it could be that there is actually something wrong with the engine that was being masked by the torque converter. Something like badly out is whack valve timing, or low compression or something equally shitty.

It's literally perfect through every gear and all the rpm ranges EXCEPT 5th. Would any of those things cause that in that specific gear?

February 6

34 minutes ago, Duncan said:

GTS4 and GTR box is the same thing, so that is not your problem. And like GTSBoy said, the diff ratios are similar (10% shorter in GTS4) and even the power and torque are in the same ballpark. I agree there is a problem with the box, not the rest of the setup, this isn't 80S commodore, it can drive up hills without changing down a gear

Well looking at the part numbers for the gears and the box between the 2, I think it was 4th and 5th had different ones. And from what I recall the ratios are abit different but I didn't think enough to cause any issue. But yeah 4th I can cruise in just fine but it really doesn't like not being in boost so gotta keep it around 3200rpm+. 5th just no matter how fast or slow starts shaking the car violently like it's on the brink of stalling at 90mph, like I didnt expect to really accelerate at all but it was so bad it felt like I was hardcore lugging the engine. I suppose I will slowly acquire all the parts to do a transmission rebuild then. Thanks for your guys' input.

February 6

3 hours ago, GTSBoy said:

The GTS4 was available with a manual, and 5th wasn't particularly taller in the GTR box than in the 20 box (if different at all, and it's probably the same).

So, it is absolutely not that the 20 doesn't have the torque to pull the gear. It should be able to cruise v. nicely at 70 km/h or more in 5th. Not up any slopes, not with any hope of accelerating if you need it, but certainly cruise.

I know this because I went from R32 auto to R32 with manual DET box (and then to 25 with 25DET box and that is where you really realise how little torque the 20 actually has, if you hadn't beforehand!). I wouldn't often use 5th below 80 because the revs were quite low and there was less vacuum and it tended to use less petrol if you kept the revs up a little more in 4th. But it was fine at 80 and up.

So, it is more likely that there is a weird/severe/unexplained problem in the box. Maybe a knackered bearing in the 5th/reverse shaft area.

Thank you! It's fine if 5th is maybe just no good, I tried going everywhere from 70mph to 100mph and it acts like the car is about to stall. Didn't wanna leave it in 5th too long though. I know 4th and 5th is abit different in a gtr but I didn't think THAT much to where the car is undriveable In 5th. Also by cruise I'd be going about 70-80mph on highway. Around 130kph I think?

I don't mind trying to rebuild a transmission myself, the worst part to me is the gtr box coming back out, did that solo. Was a nightmare.

So the gear ratios from a gtr box shouldn't be the problem? Because if I rebuild it I will probably only be able to find gtr rebuild kits and gears.

Thanks again.

February 6

Hello, so my automatic trans went out on my r32 gts4, eventually got around to swapping it with a gtr transmission.

I used the original speedo gear from the autobox into the gtr trans. And so far in 1sr,2nd,3rd,4th it works fine, but in 5th the car simply acts like it doesn't have enough torque at all throughout the rpm range and wants to stall. I assume this is because an rb20det doesn't have enough torque for 5th which is made for an rb26dett. 1st 2nd 3rd are pretty decent but 4th needs to stay in boost or it wants to stall.

It has the og auto ecu + diffs.

Was curious what could cause this or a fix as I'm unfamiliar with gearing and ratios. My ideas so far are

put in an rb25det from a stagea at some point to make 5th usable.

Take apart transmission, rebuild and swap 4th and 5th

Swap the diffs for gtr ones? Might make it worse though

Any advice appreciated thanks

It's a 1991

May 13, 2023

Hello so on my 3rd attempt with rear main seal install, oem looked flush when I took it out. 1st try it went it uneven and too far, 2nd try with another new seal it went in mostly flush but one side ended up crooked and couldn't even it out well enough. Well THE 3RD TRY AT THIS, seal looks and feels pretty even all the way around on inner and outer ring, cant even slide a piece of paper under it anywhere, BUT it isn't flush with the seal cover. It goes in ever so slightly, , maybe a few mm. Otherwise its even all around on its depth.

Now my question here is, would the rear main seal being slightly in cause any leaking? as long as its even and the surface was cleaned? It wasnt leaking before but with the transmission off I decided to do it since a 30yr old seal MUST be showing some age at this point, but when it came out it was just as soft and pliable as new one to my surprise so it wasnt needed but needs one installed now regardless.

I am losing my mind trying to get this stupid seal on and I think im good to go with it finally but just curious of others opinions more knowledgeable as ive read conflicting things saying IT MUST BE FLUSH WITH THE COVER OR ITLL LEAK, and also people saying in a bit is fine as long as its even and theres no gaps.

Thanks for any advice/help

March 6, 2023

3 hours ago, GTSBoy said:

It is vert unlikely that the speed sensor from the auto will fit into the manual. The boxes are from completely different manufacturers. They don't swap between auto and manual on any of the RWD boxes, so there's no reason to expect that they do on the AWD (which I've never stopped to think about before).

The speed sensors from the r32 gtr, r32 gts4 manual, and r32 gts4 auto share the exact same part numbers, besides the gtr one having a 20 spline and the gts4 a 21 spline. The boxes are literally the same besides a few gears that are taller in the gtr and the auto well being an auto, the transfer case is the exact same beside the whole not having a shifter bit, from what I understand.

March 6, 2023

9 hours ago, Butters said:

Both the body loom and trans sub loom are different between auto and manual.

You are going to need to change at least one of them.

Most people just change the trans loom, this leaves you with un-used plugs on the auto body loom.

Picky people will do both to tidy things up.

The speed drive is mechanical, you can use which ever matches your gearing.

I was probably going to just get a new trans loom for a gtr, since I cant find a manual gts4 one.

Id assume the gtr trans loom and the gts4 ones are basically the same exact thing?

March 6, 2023

5 hours ago, Duncan said:

To answer your questions backwards, a GTR box is a GTS4 box.

I don't know the wiring differences and I haven't looked at it personally, but GTSBoy put up detailed wiring diagrams here:

Top left of diagram 1 shows in Auto cars the start wire from the ignition switch goes via the inhibitor switch and then to the starter motor. I don't know where it is or what it looks like, but you need to bypass that. Given the diagram doesn't show any other wires involved from the gearbox, I guess it might be at the auto trans shifter.

I can't work out the reverse lights at a quick look, but I think you need to use the reverse switch on the manual gearbox as the trigger so wiring changes will be needed unless the auto also had a reverse switch. Neutral switch should not be required.

None of that is ECU related, so swapping ECU will not help

Thanks so I guess there really is no way around it without messing with some wires huh?

I should be able to use the auto gts4 speed sensor with little to no issue though correct? The GTR trans has slight different gearing but the speed gear is same exact part number in auto and manual gts4 and in the gtr gearbox.

March 5, 2023

Hello, ive been unable to find any info really regarding the wiring of the inhibitor for the car to start, nearly have all my parts together now for this.

Id like to do this as proper/oem as possible, now the question I have is if I use a manual ecu for my car will I still need to fiddle with cutting wiring and soldering to get the car to start and the reverse lights to work properly?

Are the manual and auto transmission harnesses the same?

I will most likely be using a gtr box since I cant find a gts4 box anywhere.

Thanks for any help as im clueless when it comes to wiring!

February 7, 2023

Thanks duncan ill give it a go then.

February 7, 2023

Well I havent been able to find clear info on this, I figured itd work but then ive read some places stating it will not. But was unsure if they were talking about factory wiring or aftermarket. Im aware the aftermarket gtr ecus work with it just fine but I didnt really wanna spend big money on an ecu if im gunna leave the engine stock since gts4 specific plug and play ecus seem nonexistant nearly( I havent been able to find one that says to work with a gts4)

February 6, 2023

Hello all, so ive decided to convert my auto r32 gts4 to manual but in the process of getting the parts together I cant find any good info on if the rwd skyline ecus will work with the attesa. As far as I can tell based from what ive read is they will run the engine fine but ill lose the awd, unless I get a gts4 specific ecu.

February 22, 2020

12 minutes ago, GTSBoy said:

That's not necessarily how torque works.

well yeah am an idiot an forgot all about torque, probably just gunna switch the trans out then had a glimmer of hope with 3rd barely working maybe clean the valvebody if I don't end up breaking it.

February 21, 2020

On 2/3/2020 at 7:40 PM, zoomzoom said:

The type of fluid can affect the operation under certain circumstances, but not outright failure. Before I replaced my valve body with a modded unit, I replaced the fluid with some inexpensive ATF, maybe valvoline. It caused 3rd and 4th gear to flare a lot, especially on downshifts.

In your situation I'd be tempted to look inside the valve body to see if there's any contamination or build up from old fluid like sludge in an engine. The valve body is a made up of 2 plates sandwiched together, which is then bolted to the transmission body.

Pretty tough job if you've not done anything like it though. Looking up at the transmission, it's not obvious which bolts are holding the valve body plates together, and which ones are holding the entire valve body onto the transmission. Oh, and if you get it wrong and try to take out the ones holding the valve body plates together before removing the entire body, the bolts snap.

Hello so I still haven't dropped the pan, been way too cold, every shop ive called said clutchs are bad trans is bad need a new one, but lemme summarize when this all started, 4th gear stopped working entirely suddenly, then 3rd 2nd and 1st slipped bad, changed the fluid. 1st and 2nd work fine they have 0 slip, 3rd wont engage BUT if I get the revs to 5.5k it will grab but barely, but from 1k-5k it doesn't do anything acts like its in neutral almost but at 5.5k it will half grab and the car will pull thought opposite should be true if clutchs were bad, should it not slip at higher rpm and grab at lower?

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