silversr33

Maybe not, if you had it set up properly...for me this came about after changing the spark plugs so I guess I knew it wasn't definitely the obvious ignition components. My car is much better with misfires now though it still happens...it's fixed 90% of the problem but not all of it.

Pretty sure 3.7 seconds 0-100km/h is the official tested time, I guess these bozos just managed 4.0s.

Hmm aren't new models/series usually built from june onwards tho? like coinciding with financial year, did they really introduce S2 in january?

Are you running standard boost? Running rich can cause idling issues. And it only misfires under acceleration right? First thing I'd do is put it back to standard boost and see if either the stalling or the misfiring continues. If that fixes some or all of the problem then I reckon, in my opinion, it could be the ECU flooding the ignition system with fuel and retarding the ignition timing at about 4500rpm where the stage 2 boost should kick in, and then causing a misfire.

Hey all name's Sean, have had my current r33 S2 coupe for a couple years now, was active on this site 3 or 4 years ago but kind of drifted away busy with work and stuff, and I think my account got deleted lol, anyway I can't find it and am happy to meet everyone I live around auchenflower so if you see me around gimme a wave.

Saw a silver r33 series 2 draining my wallet!

Hey whatever you guys figure out about the leak etc can you post the result/fix? Interested in how these kinda things work out cheers

Hope they catch em, should be hard to miss a trailer like that getting around.

Do you still have the standard ECU in? 4500 is the point on R33 GTS-Ts where the dual stage boost gets ready to kick it into the second stage and if the boost is higher than normal or if it's already running 7psi at the lower rev range through the factory solenoid it freaks out and tries to cut the boost a bit. If this is the case you can fix it by bypassing the solenoid.

The only dodgy rules thing I think was that they could run higher boost cos it was less displacement, but toyota used 3s-gte in racing for a long time, it's a really good engine, was used in le mans trd supras back in the 90s too. I think they mostly used it cos they could make the same hp goal (500+) they would have with the 2jz, good torque for its size, lighter and better balance etc. If you're restricted on power anyway, using a lighter engine with more boost is the way to go

Sounds similar to an extremely common problem. It's doing it as you first accelerate, you go through a zone where it's stuttering or popping and not building boost well then it's back to normal until you slow down again? Running slightly higher than stock boost? It probably is running a bit rich, would also explain the blackened tip, but it shouldn't - depending where you intend to take the car I'd be thinking about a A/F addon or better yet an ECU that can manage A/F ratios and get sorted out properly on a dyno.

Yeah, most stock ECUs in 90s up turbo cars have a point at which they'll fuel cut to prevent critical damage. Do a web search it's a very common ECU tactic, as is R&R as a less invasive, immediate measure. googled this from a document talking about fuel cut from FC rx-7s: "The stock fuel system is programmed to prevent overboosting the car by cutting fuel past about 8.5 PSI. This system is designed to protect the engine and must be defeated if higher then stock boost is run. Fuel cut feels a bit like the car hitting a wall just after 8 PSI. The Fuel Cut Defender (or FCD) is available from most of the vendors (there is also a DIY version) to trick the ECU into thinking that the car is running less then 8.5 PSI of boost, thus avoiding fuel cut." Here's one about 90s toyota MR2s "You're having a great time boosting onto the freeway. You shift into third and floor it and that's when it happens--you feel like you've hit a wall and the check engine light is on. "What's wrong with my baby?" you cry out! Worse yet, now every time you give it anything but a light amount of throttle, you seem to feel a hesitation from the car. Something is blown for sure? No, it's called fuel cut and it was built into your MR2 Turbo on purpose." I dunno, maybe you've never experienced a fuel cut, but if you have I'm sure you'll agree it's pretty hard to mistake it for anything else - boost builds, peaks, (and if you're watching the gauge you'll see it happen over 10psi in a stock S2) extremely suddenly boost is shut off completely, entire car JERKS violently, strong engine braking and just a really shocking, disconcerting experience. Tek_01 dangerous how? You mean from a safe driving point of view or dangerous to the car? In the R33 I've experienced probably 4 or 5 different fuel cuts at peak boost levels and it doesn't go into a limp mode, although I know it's capable of it and some other cars use it, in the MR2 after a FC it'll stay in 4th gear and limp along til you shut the car off and restart. The FC in the R33 cuts the fuel off momentarily to halt short circuit the system instantly and more importantly the turbo which is possibly about to blow and yeah I'm sure it's probably pretty traumatic to your components to have them do that all of a sudden but if it's that or half your internals popping apart..heh

Omg...HAHAH gold! I've seen hondas and stuff from the US trying to look like gt-rs, but this guy's from the UK where they've been readily available for years!! He doesn't even have the retarded american teenager defense lmao. I think someone needs to preserve an image of this page for posterity. In fact, fck it I'm posting it on myspace

Hmm, thing is what's happening at 10psi+ on stock ECU isn't R&R, at 10psi the ECU is in serious danger mode that's Fuel Cut. If you've ever tried to exceed 10psi on a stock ECU r33 SII, or about 12 absolute max on a SI you'll suddenly feel like you've hit a brick wall, boost will be cut instantly and it jerks the whole car very violently. First time it happens you'll probably wonder what the fk you just did to your car heh. Anyway that's when the ECU feels boost pressure getting dangerously close to stock turbo limits (at or going juuuust above 10psi for SII and r34gt-t, 12psi for R33 S1) the ECU goes boom and cuts the fuel supply which kills boost. So yeah, that isn't R&R, that's fuel cut and it's much more immediate and severe than R&R - and needs to be cos the ECU uses it when you are at or just less than 2 psi from what is considered breaking point for the stock turbo (12psi for SII and R34, 14 for SI). I'm sure you can imagine how fast an overboosting wide open throttle could build from 10psi to 12psi to 14 then boom...like maybe a second or two heh, if that. R&R seems to be commonly confused with fuel cut, and I think if I had a dollar for everytime someone mistakenly messed with their AFM, spark plugs, coils and injectors to fix a "misfire" that was being induced on purpose by the ECU retarding the ignition timing because its factory settings cause it to misinterprete mild boost tweaking as rapidly approaching turbo destruction R&R isn't as immediate or severe as FC but worse almost because it's very frequently misdiagnosed as a normal misfire where one of the spark plugs or ignition coils is missing its turn under high boost etc. The situation can be caused by a faulty AFM, but you will never see R&R at the peak boost limit, only fuel cut, and likewise fuel cut couldn't be mistaken for a misfire in a million years. R&R seems to be used in situations where the boost levels are not really even close to critical meltdown level, but the increasing boost curve is not following the boost settings the ECU expects it to, and should the curve be projected at a linear increasing rate - which to be on the safe side is what the ECU has to assume - that if something is not done it would cause potentially serious damage in a few seconds time. To control it the ECU floods fuel (Rich) and delays (Retards) ignition timing briefly, and this often results in a misfire, while the oversupply of fuel combined with momentary lack of combustion and access to exhaust causes the turbo to be unable to continue producing power at any efficient level. It can concievably happen on stock boost on very cold days etc when air is much easier to compress, and S2 and later GTS series ECU's are particularly twitchy because their lightweight nylon compression wheel spools faster than the S1 ceramic but it's also not expected to survive above 12psi while the ceramic is rated at 14. Far more commonly it happens because of even minor overboosting on R33/34s, (not GT-Rs or 32s) and always well below the danger thresholds where you'll experience fuel cut at 10-12psi. R33 GTS-Ts, R34 GT-Ts and stageas (and prob ceffies not sure) really frequently have R&R "misfire" and stuttering issues at about the 4-4.5k rev mark down low in the gear ratios during on-boost acceleration, where the boost prior to that rev point exceeds 5psi. It's cuz people use bleed valves and such to increase boost at a linear level across the rev range...which is fine for some cars, but the models listed above have a factory 2 stage boost setup as standard which runs a lower boost very early on in the acceleration to make it a little more friendly in traffic, more torquey and less laggy at low speed. Within only a few seconds of firm acceleration the ECU gets ready to tell the solenoid to switch to it's full (stock 7psi) boost for the rest of the rev range. So if you've manually boosted to 9psi, when it gets to that 4000-4500rpm range the ECU is expecting a 5psi setting to give way to a higher 7psi setting but is recieving data indicating a linear boost spike well above factory settings, not close enough to the absolute boost threshold to warrant a fuel cut but the projected curve indicates it'll get there fast. So it uses R&R to prevent it spiking to dangerous levels. For a while you'll probably notice the sputtering every time you accelerate and not know what it is, after it has been doing it every time you accelerate for a while it will usually cause a misfire when it retards the ignition. You'll struggle a bit through that rev range without boost building or sustaining, at about 5k it'll build again and will generally stay solid til redline or you hit the factory cutoff threshold (and serves you a fuel cut) depending how boosted you are. So yeah anyway, detailed explanation but there seem to be an absolute ton of people spending money on trying to fix elusive misfires that actually have nothing to do with faulty ignition components. It's also easy to avoid - if you want to boost a little at stock you need to take the stock boost solinoid out of the boost control loop cos then the first boost stage won't be initiated, which means the ECU won't go "wtf?!" at the rising boost when its expecing a second stage, so it won't try and flood with fuel or retard the ignition. There are a number of ways to eliminate the boosting safety precautions being executed too, but ultimately this all obviously relies on your ability to know what a reasonable level of boost is before you apply too much strain to stock internals. More efficiently, as above posted get a remapped ECU for your setup, piggyback ECU or fuel regulating attachment like SAFC or e-manage. I've seen pages upon pages of people posting about their R33/34 sputtering and misfiring and being told (in good faith) to go buy $600 splitfires or get a new O2 sensor etc etc. to fix a "misfire problem". Even experienced mechanics (like mine who has hand built custom drag car engines with power levels that make ours look like scooters) who aren't used to skyline-specific issues almost always assume this is a misfire caused by a faulty spark plug, coil pack, injector, etc etc until it becomes an expensive, frustrating drama that never actually fixes the boost issue, at most hides it, until you one day put an aftermarket ECU or piggyback on and suddenly find out what kind of performance you didn't realise you were missing out on. : / Often the "misfire" is really elusive and after spending hundreds on plugs and coils it's still there...other times the coils do cover it up, while in the background there's problems every time you accelerate and R&R kicks in, flooding your ignition system with fuel creating buildup that fouls spark plugs and leads to misfires....heh. Point being, if there's stuttering/R&R and misfiring, fixing the misfiring is missing the point. The misfiring is not the problem, it's a symptom of it.

Follow up: shortly after writing about this I went down to the garage, disconnected the battery, pumped brakes etc, earthed boost solenoid black wire, reconnected battery, reset ECU and took the car out for an hour long drive. It was noticeably stronger on boost, built up to and sustained up to around 0.85psi. First time in almost a year (yeah I been lazy ) I've been able to accelerate without stuttering/"misfiring". Didn't do it even once in the hour or spike any kind of boost or have the slightest negative reaction or suspicious knock or sound! Feels great I had forgotten how good this car could feel when it felt like this and it sounds huge again compared to when it was having issues lol. All without even glancing at a coil pack **Disclaimer: I do not claim to know much at all about fuel management, fuel injection systems, forced induction, air/fuel mixture ratios etc. This is a logical explanation that I've pieced together by reading a LOT of stuff both on SAU, on the net, learning about how ignition systems work, picking up info about how the R33-34 systems work from unrelated threads... etc etc. I really didn't want to end up one of those poor guys who spent $600 on splitfires and then had another misfire heh. Parts of this are probably incorrect, feel free to point them out, but I'm hoping this sheds some light on the situation because this has been a f*cking pain in the ass for a lot of us for ages It's also really long so if that's going to be one of your opening flames tough luck, I warned you It was only when I started looking for info on better than stock coil packs that I was shocked at how many people experience this *same* misfire...and then I started noticing it only seems to happen at a specific rev range on r33 GTS-Ts and 34 GT-Ts, um and probably on stageas too actually, misfiring on boost can and does happen to GT-Rs and R32 GTS-ts on here regularly, and for (usually) related reasons, but NOT at that specific rev range. In my opinion GT-Rs and R32s with tuned ECUs/or stock boost stock ECU experiencing misfires, etc are experiencing issues that appear similar but are in fact not like this problem at all. I'm pretty much positive that no-one who is running an aftermarket/tuned/SAFC-controlled etc is experiencing this specific misfire and flat, stuttering spot at a specific rev range everytime (and almost always nowhere else). If you are experiencing misfires/boost stuttering/sharp boost cut. And so....specific rev range...specific models...that isn't a misfire, it's done on purpose by the stock ECU as a harm prevention measure. I suspect you've noticed some pretty intense fuel consumption too heh, I know I have. I think there has been an awful amount of frustration, confusion and $$$$ expended because we've been mixing up similar symptoms for a number of particular common misfiring problems. You go to any mechanic, have a misfire under load, he'll go spark plugs, then he'll go coil packs, and if he's thinking laterally he might check out the injectors if the plugs have plenty of build-up, may even end up at the AFM and eventually do a A/F ratio test but rarely suspect that evil, paranoid little box is chucking a regular sad because it thinks we're having a little too much fun. Why it does this though is that R33 gts-ts, r34gt-ts, stageas, have a stock 2 stage boost solenoid (unlike GT-Rs who have two turbos anyway and 32s which...I dunno just didn't get that yet). Lower boost at lower revs to give it a little pick up, then at that magic 4000rpm spot the VCTS (variable cam timing system, introduced with RB25det onwards) kicks in and the higher level of boost takes it from there. It boils down to the ECU thinking we're going to blow the turbo because the ECU interprets the current level of airflow combined with engine speed, revs etc as a potentially harmful level of increasing boost compared to where the stock settings expect it to be at in this rev range and the ECU takes preventative action. We could most likely get right down and figure out the levels if we really wanted to but practically I guess it works out something like this. The ECU doesn't actually detect boost, it's a vaccuum line that runs the stock boost gauge. All it does is take airflow readings, compare them to what its settings say is normal for induction, boost, exhaust, whatever, and as long as they're not out by too much there won't be a problem. Overboost even a little bit and there will likely be a problem because of the first part of the two stage boost setup. You guys who claim you are absolutely rock solid factory stock standard boost and this only happened after you installed a standard mod like exhaust, intercooler, maybe even pod filter etc - these all increase airflow and with enough flow our suspicious little friend thinks we're on the boost. I suspect the number of non-boosted cars that are experiencing this "misfire" are probably very low, but I suspect (and have no proof hehe) they would mostly be R34s (free-flow perhaps, aggressive ECU boost limits) and perhaps some stageas/r33S2 for similar ECU limits. It's also quite possible if you've had the car only a short period that in fact it is boosting higher than it should be in the first boost stage and you don't know it. It takes about 2 minutes flat to insert the most manual of boost enhancers - a larger than factory diameter metal ring - into the vaccuum hose, and if you weren't acutely aware of your boost curve (eg not what it peaks at but how fast it's increasing) in the first 10 seconds of acceleration from low speed, and the peak was set at 7psi or less, you'd think you were running stock boost but the ECU knows better. And we all know what happens next: *pop*, farting sounds, you probably ease off boost to wait it out for those few hundred revs while silently raging against the fact that you paid $600 for a set of ignition coils you won't need til you have about another 70kw at the wheels and then, it's all good til you stop again. Our misfire is actually a damage prevention method often referred to as "Rich and Retarded" because at a critical point in the stock boost power band the ECU uses a harm prevention tactic which enriches the fuel ratio compared to the induction, while agressively retarding the ignition timing in order to circumvent the turbo. Why? ECU just does what it's been told to and calculations show that at the current boost level, which has been rising in a linear curve instead of tailing off as expected before the high end boost kicks in at about 4500-5000, major damage will result if boost increases at this rate and as far as the ECU is concerned this is a major snafu in the car and if it doesn't do something it's f*cked. R&R effectively prevents the turbo from making much boost at all, until it detects as it leaves the transition rev area between the low and higher boost stages that the boost is within acceptable levels (because it's spooling up again from scratch heheh) and then assuming you aren't peak boosting over about 11psi (r33 series 1: ceramic compressor wheel) and not over 10 for R34, R33 S2 or Stagea (more aggressive ECU, lower fuel cut cos of nylon compressor wheel), your boost will be back to normal and your "misfires" won't occur until you have to slow down and move through that same low gear rev range. Course those of you who do exceed the 11/10psi limits (or thereabouts anyway) are probly familiar with the consequences - an extremely nasty complete fuel cut, which makes the entire car jerk (and from memory engine brake) to prevent critical stock turbo kaboomage as it very rapidly approaches its safe operating limits. You can imagine what that kind of shock does to the engine too - not good, but better than what it's there to prevent heh. Not that I'm defending my mean, paranoid little ECU. So the "misfire", as evidenced by the fact that it always happens in the same rev range, to the same kind of car, and never happens anywhere else (otherwise you've also got a misfiring cylinder lol) shows it's actually not a misfire at all but intentional ignition timing retardation combined with fuel flooding to sabotage the rogue turbo. If you've read many of these threads you'll see another recurring theme is that many will say that they are mildly boosted over factory settings, but if they take the boost back to normal it stops misfiring immediately. Well that's one option yeah but let's face it, no-one wants to do that one. Tricking the solenoid as per this thread might work ----> http /www.skylinesaustralia.com/forums/HO...st-t42895.html Haven't tried it, I think it would work but you might still want to ground that stage 1 wire if you choose to bypass the solenoid completely and use a larger bore in the hose - eg if you wanted to run 10psi in a S1. Option two is obviously ditching the stock ECU, and have it remapped to your current setup. potentially expensive - it depends what your plans are with the car. if you can't afford that, for a few hundred less you can leave everything as it is, get a safc/emanage etc and intercept the airflow readings and lie to your ECU Those are pretty the options afaik, stick to factory spec, ditch the ECU or lie to it. And possibly just trick it using the solenoid. Don't forget to check your sparkplugs, ignition coils etc too, if this has been occurring for a while there could be a lot of build-up...and gap the spark plugs correctly when you change the boost. Also I reset my ECU after changing anything like that, but I'm not sure if it's necessary or if I just want that spiteful little box to GTFO of my life for at least a few seconds. If your vehicle does not employ a two-stage boost pattern, eg R32 or GT-R then I can't see how you could be having this particular issue (unless someone slipped you a different ECU? lol) but you may be experiencing similar disciplinary action from Mr. ECU if you're attempting to overboost too much (but I expect the complete fuel cut at peak, rather than stuttering at low speed and hard boost acceleration). You may also have an actual misfiring cylinder - in which case check your coils one by one, spark plugs, O2, etc. **As stated at the start I'm not claiming this is all fact, it is simply an explanation for a very specific occurrence over a specific and limited number of models, and which only occurs in absolutely specific circumstances, operates in exact replication of a commonly employed ECU tactic especially amongst dual-stage turbocharged overboosted vehicles, and is therefore not a malfunction, and is based on official information, observations, considered opinion, outlandish conjecture, public domain knowledge of fuel injection etc and plenty of caffiene.**