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Hey guys. I've got a rough idle issue on my R34 GTT RB30/25DET Neo. I've worked on my RB for years and this is the first time where I don't have a fkin clue why it's happening, its baffiling me. Here's a video of it in action: Long story short: My daily R34 decided to randomly start doing this weird RPM idle fluctuation thing and it wants to die on me sometimes and I've got a higher than normal pressure in my fuel line before the fuel rail which I'm thinking can be contributing to this issue. The long story: This is my daily and the car has always performed really well for me up n till now. It was tuned on haltech platinum pro (running on board map sensor) 4 months ago and did 440hp (on 98ron) and has been driving really well, no issues what so ever. Then one day (about a month ago) I came home from work, fuelled up, popped into the shops and then came back, got in the car to head home, started it and it started idling really rough. Like, I would start it and then it would instantly die on me. So I had to rev it to keep the engine alive and I had to baby it home. And it would also do this weird RPM fluctuations where the rpm needle on the cluster goes up fast then down fast like its glitching weirdly (can see on the video). Note: nothing has been changed on the engine since the tune nor has the ecu been plugged into anything since the tune. So this problem has occurred randomly and is still the same today. Also to note: this happened when the car was at full operating temp (was probably a 30 degree day). And the same idle issue will happen on cold starts. I've attached my complete list of mods here. I haven't been driving the car since. So I've plugged the haltech ecu into my laptop to check for any error codes, nothing. I let the engine idle and I watched the sensors on the haltech ecu manager, nothing odd, and no errors. Temps all look good. TPS voltage is good. I've got the haltech hooked up to a wide-band O2 sensor (pro sport gauge kit) and the afr starts off rich on cold start then eventually it goes to 14.2 like normal, so afr seems fine and normal to me. Since I've changed the spark plugs, it now won't die instanly on me but it still idles weirdly. The weird thing is, the RPM on my cluster fluctuates up and down but the RPM on the haltech shows normal-ish (no fluctuations). Note: the video was taken after I have done all the checks below. So here's the list of things that I've checked off and done on my list to try and eliminate possible causes: • Compression test: perfectly fine like it was before the tune (phew!😅). • Changed spark plugs to new ones: this helped a bit with the rough idle, old plugs were all black (they were about 3000kms old). • Did the old quick coil plug test by un-pluging one by one while engine is idling to hear for changes in rpm: rpm/idle changed as they should on each one. • Changed fuel filter: still the same. • Checked TPS sensor on haltech and it reads correcly. 0.45v no throttle and 4v WOT. • Cleaned IACV with a new gasket: nothing changed. • Swapped the IACV with another known working one: nothing changed. • Swapped CAS to a known working one. Nothing changed. • Unplugged the water temp sensor: I know it’s not this because when I unplug it, it would show some weird temp on the haltech software and when i plug it in it shows normal. • I've tried attaching the R35 PRP coil plug harness's ground cable to somewhere els on the head: nothing changed • I've tried putting a jumper lead on the negative battery terminal and then attaching it to the head and block to see if its a grounding issue: nothing changed. • I've checked the timing marks on the cams and crank all line up. • Changed the fuel pump horn relay (constant 12v mod) to a new one: nothing changed. • I've taken my haltech ecu out and then tested it into my brother's r34 with his map to check if the ecu is still fine, and it is. Now here's where it gets a bit interesting (and let me know if it's irrelevant); I checked the fuel pressure for the first time ever by tee'ing in a pressure gauge between the fuel filter and damper that enters into the fuel rail (can see on the video). When I prime the fuel pump, it goes to 43ish psi, which it should be according to the R34 workshop manual. Then when I go to start and idle the engine, it stays on 50psi. The workshop manual says that it should be about 32psi. So I immediately thought its my fuel pressure regulator and I changed it to a known working one. And still... it's idling at 50psi fuel pressure. When I take off the vac line on the FPR, nothing really changes. So then I changed the fuel damper that sits on the fuel rail to a known working one: still the same 50psi. Then I hooked up a long hose onto the exit of the fuel rail straight to the fuel tank flap to see if there are any blockages: it dropped a little bit by 2psi... So no real restriction in the return line. So now Im wondering, if there might be a blockage in the fuel rail or my 640cc xspurt injectors are maybe blocked? 🤷‍♂️ The question I have is; is this fuel pressure on idle (50psi) normal for an RB that has a Walbro 225 fuel pump with the constant 12v mod, with upgraded injectors + standalone ecu on a stock fuel rail and stock fpr? And would this high pressure be my main culprit for my shithouse of an idle? The other interesting thing I found/tested, was; i swapped out the cluster to my old stock nissan one to see if the RPM fluctuation thing also appears on that one, and it did the same thing weird RPM fluctuation on my old nissan cluster. So something weird electrically is going on that is contributing to this idle issue (maybe?). The fuel pressure also doesn’t seem normal, so I wanted to check in with you guys before i go pulling the fuel rail off (which is such a bitch to do!). What do you guys think this might be? Can I test some other stuff? Does the haltech platinum pro ecu have a diagnosing feature of electrical components that I can try? It can't be the tune/map because it ran perfectly fine for 3 months after the tune and no one has touched the map since. The next thing I’m tempted to try is injector cleaner which I've never tried before. Can I pour it straight into the feeding fuel line instead of in the tank? Can injector cleaners damage stuff when not diluted in the tank? mod list.txt

Hello, this is definitely my favorite forum. I always manage to resolve my issues when I come here! However, I’m dealing with a problem I’m not sure how to address. I’m hoping to receive pointers or guide on my quest to solve this issue. Issue: On cold start, my swapped 180sx with an rb25det will crank and idle normally, but as soon as it starts warming up. There’s a subtle backfire, little pops if you will. At operating temperature, the idle begins to fluctuate up and down between 800-1200RPM. Eventually, only when fluctuating RPM it will drip my 150A breaker at the battery and the g4+ ecu will lose power and shut off. Or the ECU will shut off without dripping the 150A breaker and everything else stays on: radio, fuel pump, gauges, etc. Questions: 1. What may cause the ECU to turn off? 2. How to I measure voltage to the ECU? 3. Is it possible there is a short causing the current surge to drip the breaker and make the ecu behave erratic? 4. Anything I should check? Parts installed before problem began: • GTR R35 Coilpacks • Bosh donut knock sensors • PRP trigger kit • 270A alternator • LINK G4+ lambda CAN wideband sensor I did drive the car with all parts installed with one issue. The ECU had a wideband sensor overheated code, which I resolved by addding a 200uF 12V capacitor. Other than that, I didn’t deal with issues until this. Any help is greatly appreciated. Thanks!

Hi guys, I don't drive my R33 GTR often but this morning started noticing that my car's RPM gauge (stock factory) is acting funny in the sense that it would sometimes get stuck at 5,000 RPM and then not rev over that and then come back down again and then sometimes it spins up and down a few times and resets to 0 again. I don't think it's a mechanical or engine issue and my car drives normally but perhaps it something to do with the gauge or the wiring itself? Has anyone experienced this and how did you fix it? Thought I'd check here first before taking it to a motor mechanic. Cheers, Alex

Hi guys, does anyone know the different angles of the throttle butterfly valve with respect to the rpm range of the engine? I also need to know the air flow rate with respect to the rpm of the engine. The engine must be a rb25det, preferably running with stock turbo, stock boost and stock intake manifold. I know most of the info can be obtained by consult software like Ecutalk, but I don't have access to a consult cable. I need the info for some CFD work. Any help would be much appreciated! Sam

Hi guys, does anyone know the different angles of the throttle butterfly valve with respect to the rpm range of the engine? I also need to know the air flow rate with respect to the rpm of the engine. The engine must be a rb25det, preferably running with stock turbo, stock boost and stock intake manifold. I know most of the info can be obtained by consult software like Ecutalk, but I don't have access to a consult cable. I need the info for some CFD work. Any help would be much appreciated! Sam

RB20 high RPM breakdown please help! Hi everyone, so I've got some issues with a project car I picked up and I'm hoping someone can help diagnose it with me, I'm well and truly out of ideas. So, I bought a super clean 180sx with an RB20 conversion. It was a non runner and I decided to do it up (why?! lol). Basically the car hadn't run for years. I compression tested it and that was fine, then realised there was no fuel at the filter, so I figured I'd buy it as it was likely a dead fuel pump. Long story short, the pump was messed up. I dropped the tank, drained it and did the following: Added a new Walbro 255 Got the injectors cleaned and flow tested (they were stuffed but came back to life and flowed almost identically). Sprayed some cleaner in the fuel rail and FPR. This got the car running. It wouldn't boost well so I thought the wastegate may have been stuck open (it had a high flowed T04 on it with a Nitto 40mm External gate). I took that off and found the gate was fine, but the turbo's rear housing had a crack in it and was no good, so I bought a T04E for it and had the dump pipe flange matched to the new turbo. The new turbo has a smaller CHRA than the old one. So I put it all back together last night and it's laggy but it wants to die high in the rev range from about 6,000 RPM. If I hold my foot into it, it will hesitate for a bit at that mark and then clean up and boost to 9,000. Now please, I realise RB's have a rev limiter. I'm not sure if the tachometer is accurate, it's likely out. So after that I went and bought a set of spitfire coils and I'm getting the exact same issue. Revs to mid-high RPM and as boost starts to really come in, it dies. The gauge only sees 3psi max. I've put a different gauge on to confirm this. So in summary: * New fuel pump * Injectors cleaned and flow tested * New fuel filter (admittedly I started the car with the old filter after I ran fuel through it into a bucket looking to clean the lines, bit of a brain fart but I doubt that hurt it) * New T04E turbo running gate pressure on the nitto external gate * New splitfire coil packs * New spark plugs BCPR6ES at .8mm So where I'm at now I'm just completely scratching my head. If it was the AFM I'd assume it would rev poorly throughout the rev range. I have a mate who says he had the same symptoms I'm having from an AFM, so I may change it. There's a ticking sound from the engine bay that I've isolated to be injectors/fuel pressure regulator. Could the fuel pressure regulator be shit? The injector guy told me it was working. It's just the stock one. The only other thing I can think of is the Walbro fuel pump is not getting enough power. I've checked it at idle and according to my multimeter it's getting 11.9-12-ish volts. Haven't done a voltage drop test yet. My thoughts are: Hard wire fuel pump to battery and just use a switch so it's got constant power. Add an adjustable FPR. Maybe switch igniter, AFM, etc. If anyone has any ideas, I'm all ears and would really appreciate it. I've read a bunch of tech articles trying to chase this and I am 100% over it. I know it's something simple but it's eluding me. The only other thing I can think of is the turbo is too big for the fuel system but I doubt this is the case as I'm only seeing low boost and after the hesitation it goes for the last tiny bit of the rev range. Any help is greatly appreciated!

Power FC problems (sr20) Hello guys, I am new to this forum. I am just your average 21 year old dude who bought a Nissan 200sx S13 with a SR20DET and I did some modifications. I assume this is gonna be a long post, but please bear with me. So I started my car after 1.5 years and during those months I bought several parts. (Apexi Power FC Djetro, S15 turbo, 555cc nismo injectors and different things but that wont matter) Anyway, 2 days ago I started her up and it went great, except for getting the car to idle. It just WON'T idle at all. I found out that my injectors had the wrong latency. I did 66% and 0.72ms and it should've been 66% and 0.10ms? So I changed that and after a few resets and start ups it went great. First 10 minutes idle, amazing. 800-900rpm, car not shaking. Then I had to turn on the A/C which I dont have. I thought using the climate control and do some cold air would do the trick. Well I guess not. Car was doing weird things. 480rpm-900rpm over and over, here is a video; https://www.youtube.com/watch?v=GZXVeiSi1y0 I don't know what to do. My map sensor and IAT are working fine. The car was idling fine but I had to complete te self-learning process. My defroster doesn't work either because some cables are missing. (I found some cables so I am gonna try it out tomorrow, it might work) Other things that you guys might find interesting; My O2 sensor stays at 0.0v, even at idle. I found out today that there is a fat O2 sensor in the elbow, and the redtop ECU uses a Skinny O2. (I had a black top ecu, so this is why there is a fat o2 in there. Black top = fat o2 || redtop = skinny o2) Can it be because of this? How much influence does the O2 sensor have when it comes to the self-learning process? Also, the car starts with boost control on. And I don't even have a boost controller. (I turned it off) My mod list: 555cc nismo gt28 turbo Apexi Power FC D-jetro Apexi powerfilter aftermarket IC HKS wastegate Mishimoto rad AEM Wideband (haven't hooked it up yet, I don't know much about this thing. But it was necessarry for tuners?)

I have been struggling with this issue for a long time now and I cant seem to get it sorted out. When i let off gas the engine either dies or comes very close to it. While driving if i let off the gas to prepare for a turn the engine RPM drops so low that it looses oil pressure and power steering stops working for a few seconds until the engine recovers and bounces up to a good idle. Also can not get any good pull out of it because when i clutch to change gears the engine wants to die. I have capped the turbo inlets and charged the system up to about 20 psi. I found a few minor leaks and patched them up. I also isolated and capped anything that is not necessary. I removed the BOV's and capped it. Plugged the vacuum, line that actuates the BOVs. disconnected the PCV and capped both lines. I also capped the line going to the charcoal canister. I can not figure out why this is still happening!!?! Any ideas? While trying to correct this issue over more than a year now I have: Replaced the plugs Replaced the coil packs with splitfires Ordered new blitz BOV's (not usuing BOVs currently) Replaced both MAFs Installed greddy intercooler piping Replaced all post compressor worm style clamps with t-bolt hose clamps. ALL of the equipment I mentioned was NEW I also have an APEXI Power FC ecu but havent yet got a tune. Whether im using the stock ECU or the Apexi running a base map, it doesn't change the issue either. I am Stumped guys. Hopefully someone has an idea of whats going on!! VIDEO BELOW (not sure how to embed so i tried a few ways) <iframe width="560" height="315" src="https://www.youtube.com/embed/y_4PPMdgUYk"frameborder="0" allowfullscreen></iframe>