DatsunBanana

Had an interesting couple of days. Have had a high revs misfire and rough idle but without any error codes on my R34 (RB25DE+t). Had some used Benchmark coil packs already so fitted those plus brand new plugs which fixed the high revs issue but still had rough idle and now it started throwing code 21. It felt like failing (but not completely failed) coil pack misfire so started swapping one at a time for one of the original coil packs (hoping I was using a good one) but still getting rough idle and code 21. Revs above idle were smooth. I tried Datascan to switch off cylinders but couldn't narrow it down. Decided at that point I may as well try changing the coil pack loom as I've had a spare engine sitting in the corner of the garage for a couple of years. I whipped off the cover and to my delight found a set of Splitfires. Fitted those and the loom but it was still idling rough (but at least no code 21 anymore). Took it out on the road and it drove lovely. Stopped at the side of the road and the idle was smooth as anything. Got home onto the driveway and it was rough again. Started wondering if my steep upwards sloping driveway might have been causing the rough idle all along. Although it seemed like a crazy idea I drove back onto the road ... smooth idle. Back up the driveway ... rough idle. Repeated a half dozen times and it consistently idles rough with the nose pointed up the drive and idles smooth on the flat. Anyone ever heard of anything like that before? All I can think of is fuel pressure. I've got a Walbro but I got that second hand so could be tired. I've been doing these tests with 3/4 to 1/2 tank of petrol but could that moving to the back of the tank affect pressure? And why would it be fine at anything above idle? Any other components or internals that could be affected by an upwards incline? Oh and from a cold start, for the first few seconds it's quite smooth till the revs settle a bit then the rough idle becomes noticeable. It's roughest while cold but less so when it's warmed up.

Sorry can't answer your question but my R34 auto also came with none of those dash lights working. Didn't give it a thought until I saw a video online showing one with lights working. I couldn't find any info anywhere by searching either but I wondered if it's a thing for people to pull a fuse if they don't like the lights?? Mine also didn't have the lights working on the centre console but that was just bulbs so I changed those.

Nissan Datascan software has some of what you want but won't show pressures. It'll give you most other sensors though and has some useful diagnostic features. I sometimes use it on a cheap 8" Windows 10 tablet with a bluetooth dongle in the consult connector and charge off a USB cigarette lighter adapter. I just velcro it to a removable block of wood that slips tightly into the slot/tray below my single din stereo. No fancy on/off control though. There's also a lite android version of NDS which should work nicely with a double din android head unit instead of customising the dashboard.

Here's a summary from my experience and from the other guys who posted in this thread - and before that from reading 666Dan's legendary thread (many times) and others on this subject. I know it's a lot to take in and I remember that I still had a few questions I just needed some reassurance on. Assuming you've put GTT injectors on, you can run a standard GTT manual ECU (it'll work on the auto or manual). You can always nistune it later but until then keep the boost at actuator pressure - about 6-7 psi. If you use the standard R34 DE Y-pipe inlet, disconnect the butterfly valve plug cos the GTT ECU will send different signals on that pin. You'll have to tee into the pipes somewhere for the turbo water return and you'll have to make some custom j-pipe solution. I've done this without changing the loom at all. If you want to try the R33 inlet you need to search for what to do about the throttle body and idle control plugs as pretty sure there is some difference. That's where loom changes might be needed but maybe not if you swap the correct R34 parts onto the R33 inlet. You won't have to tee into pipes for water return cos its on the back of the inlet. There's nothing for the butterfly plug to connect to so leave it loose. All the standard R33 IC and inlet piping should fit so no custom work for that. The larger ports on the plenum will meet a restriction against the smaller NEO DE head ports but my opinion is that who cares about airflow not being perfect when you've just gained a load of boost. If you want to use the Greddy/Freddy I think that's a lot of work anyway even doing it to a standard turbo car so probably even more research needed there. Loom changes might be needed for this but not entirely sure.

Just wondering if this is normal ... if I lift the lower part of the drivers side wiper arm it rises by a good inch as seen in the pictures attached. It feels like it's against spring pressure somewhere under the scuttle panel where the motor is. I think it must be right to allow for the wiper angle to change as it comes up the windscreen but thought I'd ask in case it's the reason for my squeaky wipers. Thanks.

Did you get this sorted? If not I'll try and remember exactly what I did ?

I think like Kiwi says if you have the R33 stuff you may as well use all that but I think the throttle body electrical plugs might be different which is why you'd use the R34 one. Someone will correct me if I'm wrong. The R33 turbo plenum has some advantages ... ports are bigger although I don't remember if the DE head ports match that size. Good thing is it will have a water return hose fitting on the back and I would imagine it's easier to get at spark plugs and coil packs when you don't have to remove the y-pipe every time. Plus if you're changing injectors you have to take it all off anyway so may aswell change it. Having said that I just kept the R34 y-pipe and disabled the butterfly. It closes with vacuum pressure so when disconnected it will open up the plenum anyway.

If you've got an R34 non-turbo then you can fit brakes from other models but you have to do caliper and discs together unless you have some sort of bracket to change the distance of the caliper from the disc. I would also be inclined to do a full set not just rears as mentioned above. I swapped out the smaller discs and slider style calipers on my R34 GT for a full set from an R32 GTR. Most (maybe all) R34 non-turbo models will have a 14mm bolt and therefore a 14mm hole in the mounting. If you swap for brakes from an R32 or R33 they'll have a 12mm bolt you'll and will have a 12mm thread in the caliper. You keep the 12mm bolt and just put a stainless steel sleeve in the mounting hole (14mm outside diameter with a 1mm wall thickness). The mounting hole centres line up perfectly. Braided lines would be sensible too. I haven't had any braking problems or hydraulic imbalance but some say to change the master cylinder as well to match the bias needed for the brakes you use. You also have to cut the lip off the backplate/dust-shield or change them for bigger ones to match the discs you use. I cut mine. If you use brake lines with banjos then you may need to cut the banjo bolt a little shorter.

Are these the same for the 124 pin ECU on an R34 too?

Shane Lynch (of Boyzone) drifted a VH45DETT for Japspeed a few years ago over here.

It's this on my 25DE NEO - Highlighted on the page here if you click the link ... https://nissan.epc-data.com/skyline/er34/3951-rb25de/engine/165/16523P/ Click it on the picture to find part number 144655L300 As far as I can tell it's got the same part number for RB20DE Laurels but just to be sure, try and find the exact one in the EPC database for your model starting here ... https://nissan.epc-data.com/laurel/ From memory it's soft rubbery plastic and has a flange on one end so it doesn't disappear into the airbox. So not quite the same as a rubber connector but if you want to improvise then something like self-amalgamating hose repair tape wrapped around the TB might do it. Or even a couple of turns of duct tape - anything to create a soft seal.

Couple of times I've had the circlip on the turbo actuator arm fall off and the actuator disconnect. First time it was on a CA18DET and ran absolutely gutless. It's also happened on my RB25DE (with turbo conversion) but wasn't as bad cos the compression is higher so just felt like it was running non-turbo again.

I had code 21 on my R34 (non-turbo) and a lumpy idle. It ran fairly well while driving though. I can only speak as I found but changing the coil packs fixed it. O2 sensor should be swinging between higher and lower values. Recently I had to change my sensor as it was stuck on a single value and failed the emissions tests we have here in the UK.

Or you can take on board the different opinions and decide what works for you. There's nothing wrong with a +t but there is already a lot of info on here so check all that out and get a project thread going if you decide to do it. I wanted the challenge of a project but the cost of a turbo engine in the UK was beyond my budget and I didn't want the hassle of selling mine to buy another. Keep in mind there's more to it than just the engine upgrades. At least brakes, hopefully suspension, maybe gearbox depending on power. If you do a +t it'll drive different than a GTT (not a bad thing just different) and have a lower power potential. Dropping in the turbo engine would be cool and a nice project. There'll be all sorts of advice - some of it might even be from people who actually did what they're suggesting ?

Or do you mean putting that turbo and intercooler on it? Go for it! A few on here have done it. Mine's been +t for over a year now and I love it.

Someone else had a similar problem here though no solution was ever posted ... http://www.skylineowners.com/forum/21-tuning-technical-questions/144927-help-r34-speedo-not-working-after-rb25det-neo-conversion.html Bit of a different situation than yours but I've bolted a turbo and supporting mods on to my auto GT and now running a GTT manual ecu in there. Speedo works fine. I don't know why yours doesn't after swapping the whole engine.

Hi, does anyone know if it's possible to use an R34 RB25DE torque converter on an R33 RB25DET? Housing part numbers are the same so I'm guessing the parts will physically bolt on to flywheel and that the splines will fit the propshaft? But what about the stall speed and handling the power? If anyone's done it would be great to know if it was successful. Thanks.

Awesome - I'm in the wrong country :-)

I don't think anyone's pointed out yet that the power you can get from a genuine DET will always be more and easier than from a DE+t. So if you have a particular power figure in mind you might only have one choice really. I've done the DE+t and the sense of satisfaction is pretty awesome. I'd have had to wait a lot longer to buy a GTT and the moment might have just slipped away. Keep saving and watch the prices rise. My budget would probably have got me a GTST at the time but I wanted the R34. It might have been non-turbo for a few years but at least I was driving it. I gradually did the supporting mods - brakes, suspension etc. before the turbo conversion. If you're ok with spanners it's not hard, not particularly time consuming and not that expensive if you're patient about looking for good deals.

No worries. And welcome by the way.

Try the thread here. Links are still working - http://www.skylineowners.com/forum/21-tuning-technical-questions/143203-nissan-skyline-r32-r33-r34-service-manuals-links.html

It is a vacuum canister. I removed mine for a de+t conversion. If I remember correctly vacuum came from the inlet plenum to this and then out again to the variable air intake butterfly valve solenoid. Another pipe goes from the solenoid to the butterfly actuator. I diverted the plenum take-off to my boost gauge instead. And I disconnected all the tubes from the solenoid. So this was redundant for me.

That's great. Thanks for confirming.

I'm gathering parts for a manual conversion on my R34 25GT. I know the RB25DET box is physically a lot fatter and stronger but in some side by side pics on the web it actually looks a little bit shorter than the RB20/25DE box. There's also a pic out there of the 25DET box with a tape measure against it showing about 32 inches and the 20/25DE box I got already is more like 33 inches. Does that sound right that the weaker box is actually a bit longer? This info is to help me buy the right tail shaft. It would be equally useful to know the actual length of the propshaft front piece from an R33 GTS or R34 GT. Anyone got that info?

OK. I'm hoping there's one on the box when I see it tonight. I found out that it's off an R33 so at least it will take an electronic one if not already there.