Neostead2000

8v - 2.48ms 9v - 2.15ms 10v - 1.74ms 11v - 1.41ms 12v - 1.15ms 13v - 0.99ms 14v - 0.89ms 15v - 0.82ms 16v - 0.81ms I'm running these values on my RB20 Neo with 570cc Denso R35 stock jets and it's great. Also bought a set for my Legnum VR4, love these injectors!

Hey Kaz, Unfortunately I am not at home currently and wont be for a few more months so I do not have access to my files or CAD. And at this point I prefer to keep the files to myself as I want to potentially make a few more pairs and see if they will sell within the EU before openly marketing them. But the way it's shaped and how small it is, I don't think you can fit both an indicator and a fog light onto the same surround, unless they were very small LED-type clusters.

Well the things I make are entirely custom and built from the ground up, unless it's a factory replacement part like the GTR Indicator surrounds. I made a slight revision to the gauge panel and now it can be printed in 3 separate main parts, which then get assembled simply by using some grub screws. I already sent one to a chap in the UK and he seemed very happy with it. I just checked and the shipping cost to the UK is about the same for Australia too, about $12. The good thing is now the panel can be placed in a bubble envelope which allows the quicker and cheaper shipping price.

Update on this. I didn't chase the dual filament bulb idea simply because after looking more closely at it, it was way too big to fit inside the parker light section. I also didn't want to cut the housing and add another light source near the parker. So I used the GTR surround CAD file I had designed and slightly modified it to fit a Micra K11 indicator (the one on their fender). It uses a 5 Watt bulb so now the dilemma was fixing the quickly flashing relay. This was easily remedied by buying a plug-in 3 pin relay which has a knob to control the pulse, cost me $5. It goes in the place of the factory relay under the steering wheel. The indicators now all blink properly and even though this Micra indicator is a tad smaller than the GTR one, I find it sits more neatly in my custom surrounds and should be more than enough for tech inspection and letting other see my intentions on the road!

Got the panel finalized and printed. Wasn't too fussed with smoothing it out at this point because it was the prototype and going into my own car, but I'm super stoked with how nice it fits. They are angled perfectly when you glance at them from the driver's seat; not too low, not too high, and at least the left hand doesn't cover the 2 gauges from the left going right. I might offer to make these and sell to people, but I'm unsure how many people would be interested in it, also considering I'm in EU so shipping would be a pain? Let me know what you guys think

I haven't done this page any justice. Initially I wanted to keep it regularly updated, but I've had some moments of pause then moments of too much progress and too many pictures, so I failed to catch up. I decided to make an Instagram page to showcase the entire process with even more pictures, so if you're interested in following up, please do drop by: https://www.instagram.com/skpro_jects/ If I can find the time, I will update it here also, but I really cannot find the time. I'm doing 10-11 hour days every day to get this Skyline finished up by the end of this year!!

Actually I do not know and cannot find a regulations sheet anywhere. I'm more worried about whether people infront of me would be able to see whether I'm indicating left or right, and I assume not since right now the only indicator is on the side fenders.

I soon have to pass initial inspection (rego) and they check for functioning parking lights as well as indicators. As I understand it, the R33 in general has 1 indicator light at the front of the bumper, one on the side of the front fender, and 1 parking light inside the edge of the headlight. I am running an S-Roc Greddy front bumper which came without any indicator facets and I am reluctant to gluing on LED strips or drilling holes. My other car has a very similar headlight design, but the corner parking light is a dual filament bulb which glows dimly at all times but when you use an indicator, it starts blinking with it more brightly. Could I take that same setup and apply it to the R33? I could find a socket with 3 wires (two signals and 1 ground), then use the same 21/5w bulb. Then splice the fender indicator signal wire to 1 wire on the socket, splice the other signal wire to the one for the parking light, and connect both ground wires to the third wire on the socket. Would this work?

UPDATE to my own enquiry from October 11. It turns out my belt WAS in fact overtightened, and upon re-reading the factory belt tensioning procedure, I believe I simply did it incorrectly the first time and added extra tension on the pulley. Basically the FSM says to install the tensioner pulley and spring, time the belt, then leave the pulley nut LOOSE and turn the engine over by hand more than 2 times (I did 4 full revolutions). After that, you need to hold the pulley with a hex key without moving it further in or out, simply keep it there while you torque the nut to 52-55Nm. I did that a second time now and I could feel the belt was looser this time around. Started the car multiple times afterwards and the belt whine completely went away!

Ok another update dear god I hope this is the last one!!! I managed to make the car start and work with the custom 24-1 trigger disc! I checked the CAS connector signal wires once more and noticed that pin 4 (1* crank) signal had 5 volts as it should. But pin 3 (120* CAS) signal had 0.223v, which should be 5. I then suspected the ECU itself, as I noticed it had been opened before due to the warranty stickers being slightly off. So I took it apart, carefully separated both circuit boards and started looking at it dumb. I traced the 41+51 and 42+52 pins and they went to Jumper locations which seemingly had no jumpers positioned on them. It appears the previous owner must have swapped them or it may have come from AEM this way. I placed the jumpers on locations JP1 (1+2) and JP2 (1+2), leaving JP3 and JP4 disconnected entirely. Placed everything back, selected the right type of signal (falling edge if going from 5v to 0) which is CONTRARY to what AEM have listed on their instruction sheet. I put the CAS back in ballpark area and what do you know, she fired right up and running even better! I quickly set the timing back to factory 10* advance and now it's running fully sequential injection and ignition. Basically the takeaway is, AEM is absolutely trash with very misleading instructions and outdated information. To think they still offer these series 2 ECUs for nearly $2000 or more is insane. I paid $1100AUD for mine so I guess it's worth it. Now I can finally focus on tuning this damn thing!

That's actually a good point you two discussed because when I tuned my Mitsubishi, the VE table was a true % efficiency table with psi load on the Y axis and RPM on the X axis. It was very straight forward; I knew that *in general* my motor was close to 100% efficient around 5000-6000 RPM so I knew around those load cells I would have to aim for pretty much 100% VE as a value, and when I was done tuning it, it took a very nice form and had logical steps from cell to cell. Now when I jumped onto this AEM, Josh is right, it doesn't have a "true" VE table. It just has a fuel map that you can set to be based off TPS or psi load (from the MAP). I chose MAP-based of course, but I noticed the values did not correspond to VE percentage, but rather you could choose, as GTSBoy said, whether to display the values in injector ms or RAW. And the RAW value apparently just goes up to 255 because that's the max value programmed into AEMtuner. This threw me off when constructing my initial base fuel map because now I had no bearing on the value scales. However, after further tweaking with it, I understood that it's just arbitrary numbers. What's important is to have a decent and logical AFR map, then have a good, calibrated O2 sensor to compare against and simply start adjusting the fuel map on a cell by cell basis, until my target AFRs match my real AFRs. In the end, the map should take a similar shape as if doing standard VE table, and the VE is still static based on the hardware so there was not much point in getting hung up on that. I'm still learning, this is only my second car that I have started to tune so I'm in no way an expert and clearly lacking some further understanding, but I will get there eventually. Also slight update, I ended up buying a metal spatula from the general store. It's normal steel, 0.3mm thick precisely. I took it to a laser cutting studio and had them cut out the disc from it. It was near perfect, just needed a light wet sand with 120 grit to get rid of any potential burrs from where the laser starts it's beam. It looks proper and fit incredibly snug onto the shaft, slightly better than the OEM disc I might add. There is also plenty of space on each side of the disc inside the optical head. And of course, AEM failed me once more. I loaded up their custom settings for their custom disc and guess what? NO START! I swear with this car, it's 1 step forward, 2 steps back. I had a starting, running, perfectly idling car with the stock disc and custom settings. And now with an exact copy of the AEM disc, and with their proper settings which are meant to be PnP, it doesn't even get spark or fuel. If I set the crank signal to read from both rising and falling edges (which normally you shouldn't do), then it makes spark but no fuel. And when I try to time it with a light, I only get a flash at the start of the crank and at the end. Gonna give it 1 more day today and if I can't make it work, I'll throw in my stock CAS disc...

I took a genuine 33 GTR indicator Surround from my buddy's car (left side), spent quite a lot of time measuring every single angle and dimension, then drew it up completely from scratch in solidworks. A friend has a 3D printer and we ran 1 prototype which fit but needed very slight adjustments. I then mirrored the surround and printed the right side which fit perfect. I will have to print 2 more for my S-roc bumper and may even offer to sell them online if people are in the need for those. I'm also currently finalizing a single DIN triple gauge panel for 52mm gauges which are slightly angled towards the driver. The panel can fit under the HVAC unit, however I am missing the radio bracket as well so I need to make that first. I will post pics once I get those made.

I'm guessing this is the go-to timing belt whine thread, so may I also share my issue. It's a brand new OEM Nissan (pitwork) timing belt and tensioners, stock 20Neo cam gears (clean teeth), perfectly timed, followed factory manual tensioning procedure and rotated the motor a few times. Afterwards the motor sat like that for nearly 8 months, and just the other day I fired it up for the first time. It makes a noticeable whirring sound almost exactly like in the above video. I have attached a video of me twisting it 45 degrees and also pushing down on it. To me, the tension looks and feels right for a performance motor, and would assume it's normal for it to be noisy when new until the rubber smooths out and overall stretch sets. You can see that this Nissan belt has almost a leathery texture on it. That said, this is my first ever RB motor so I cannot compare. What do you guys think? 386933436_6671508806232360_1461388097453349415_n.mp4

Just updating some threads I started (because f**k when people never come back to say what happened!!). After making my own engine loom with the single ECCS relay next to the ECU connector, the car fires up and runs fine with no lights on the dash (aside from the HICAS which I have yet to troubleshoot). The extra connector does in fact appear to be for the ABS module which never came on my car, so it must have been put there from the factory as a default option. Also the TOAD alarm was easy to remove. I pulled out the cabling from the engine bay (for the extra horn and hood switch), then the signal wire from the trunk latch, and then tidied up the ignition barrel wires from which they got the power from.

It very much supports Speed Density and that's how I have it configured and will be tuning the car. You need an accurate and working IAT sensor in order to get the right density calculations, though. I opted for a BMW E46 IAT M10x1.5 threaded sensor since that one is identical to the one used on an R33 GT-R, direct replacement.

HUGE UPDATE!!! SHE STARTED! In the most random fashion, the universe sent a savior right to my doorstep. A guy showed up who apparently doesn't even do cars for a living but he has experience with AEM 1 and 2. He took a quick look at my setup and found 2 problems right away. Firstly he said I needed to change my windows settings to allow the decimal point to be "." instead of ",", then to allow it to run up to 2 decimals. Apparently this makes AEMTuner let you do precise numbers and various other things. Secondly, he said I couldn't set the timing right because I was using the wrong resolution for the teeth sync. Meaning, since the EMS expects 6 teeth, the synchronization will be between 0 and 6 teeth maximum. And what I was doing until then was inputting big values such as 20, 50, 100, 180, 256 even (max value) and always wondering why the timing was either +60 deg advanced/retarded or marks not even visible... So I set my "Ignition sync" option to 1 and started measuring the timing while cranking. We slowly upped that value to 1.395 teeth which essentially tells the ECU that the CAM reference signal is 1.395 (out of the 6) teeth away from true sync. At that point, the timing was very close to 0, I think we left it at 5* retarded of TDC. The guy was 100% certain that it should fire up if we got the timing at least close to 10 BTDC. I honestly was not expecting it to start up so I didn't even have my phone in my hand, but as my friend went to crank it one last time, the lil' RB came to life like it was nobody's business!!!! It started so nicely and quick, and it held I think 1600 RPM super smoothly. We quickly saw that there were a few minor issues such as an oil leak at the brass T fitting for the oil feed, #4 injector not firing (tested it in different ways, we suspect its blocked), and it seems i have overtightened all the belts so they were squealing. But she fired up and ran, that's what matters. From now on I can take it from there and set idle tune, AFRs and take care of the belts and leak. Additionally, Zeth from NZ worked out that the injector/coil phasing was in the right order, but the tooth count was incorrect (set incorrectly by AEM, as with many other things, which I highly suspect was so that you are forced to buy their disc anyway). He told me to set my phasings from 0 to 6, again, using the logic that there are only 6 physical slots from which the ECU reads from. So, for anyone reading who wants to start his RB on an AEM Series 2 ecu with STOCK 360+6 Nissan CAS wheel, here are the settings which hopefully will help you out and save you time and frustration! For the phasings, RB fire order is 1-5-3-6-2-4, but the phasings must be like so in order to retain that order: Inj/Coil #1 = 0.000 Inj/Coil #2 = 4.000 Inj/Coil #3 = 2.000 Inj/Coil #4 = 5.000 Inj/Coil #5 = 1.000 Inj/Coil #6 = 3.000 Then you start cranking your motor with the timing light (blue loop on the back of the harness is perfectly fine) and start increasing the "Ignition Sync" value slowly. Maybe start with 0.5 and go up to 1-1.2 which should make the balancer marks within view. Then adjust it by the decimals so 1.255, 1.258 etc until you get it to your desired timing. For a 20 Neo it's 10 BTDC, for a 25 I think it's 15. You may also have to adjust your CAS clockwise (retard) or anti clockwise (advance) to get it super close. That said, I'm aware this is NOT the optimal setup since it's still doing batch fire which can get sketchy and I assume I may have issues at very high RPMs, but for the time being, the important thing is the car can start and most probably drive fine with more tweaks to the maps. I will end up making my own CAS wheel once I get the material. I hope this will help somebody 👌

Edit: After spending the entire Saturday reading about cam synchronizing and discussing it with a great fella from NZ (props to Zeth) as well as reading through the inbuilt AEMtuner info boxes, I have a slightly better understanding of what may be happening. The AEM EMS is hard coded to read a 24 tooth wheel for 1 full engine cycle (720*), or 12 teeth per 360* revolution, period. AEM have inserted a "stock 6 cyl Nissan CAM disc" option for some reason which loads up with 6 teeth for spark/fuel/wheel. When you view information about the "Spark Teeth" option, AEM say: "Is usually set to the same value as option Wheel Teeth for sequential ignition and set to half of Wheel Teeth for waste spark ignition. " So, if you wanted to run waste spark/batch fire, you would set the spark teeth to let's say 12, and wheel teeth to 24. Otherwise if both options have an equal amount of teeth input, it should work as sequential. ODDLY, the stock setting of 6-6-6 (teeth) right now on my car makes it do wasted spark, but that is because the magic behind all the calculations and the way AEM have built their transcoders or whatever they're called. In other words, these coils will always do batch fire if you run the stock cas, simply no way around it. And that is if you manage to even start the car at all! This explains why my coils are firing the way they are. There is still much to learn, but I have already lost an entire week trying to make it run. It almost looks like there is no way to make the AEM read the stock CAS properly, so I will have to resort to making my own trigger disc by getting the thinnest piece of metal I can, then manually lapping its face for hours until I get the desired thickness. I've been told by an AEM user that he's done this to at least 5 different cars with custom trigger discs and they're still running flawless. I'm writing all this so that people (like me) in the future could have an up-to-date reference about this issue without having to read 20 different posts and talk to 10 different people and watch countless youtube videos. Will keep updating!

I have traced each coil signal wire to its corresponding pin at the ECU, and they all match properly. I've double checked that my Crank 1* signal goes to pins pins 42+52 and my Cam 120 deg signal goes to pins 41+51. I cannot find an option within AEMTuner v3.2 to switch from batch fire to sequential like it should be. I'm literally stumped.

You're right, I found it, the 1st one from top down to attached to the fusebox under the steering wheel. It functions and gets warm when I keep cranking the car. I drew up the CAS disc no big deal, but I phoned up 20 companies and nobody has material that thin, not even 0.2mm aluminum or steel. So that's out of the question. And I called up some parts suppliers, nobody has the AEM wheel in stock, needs to be ordered from the USA... I did get some progress made today but it was more me understanding how things worked and not so much making the car start. I took all 6 coils out on top of the manifold (without removing the neo Y pipe, im a master on this engine now) and put the original iridium spark plug in each coil. I took the cas in my hand and started spinning it to double check if I have synchronous ignition, and I do. I took a slow-mo clip of all 6 and here is how the ignition goes as I keep turning the cas: Cyl 3 & 4 fire at the same time once Cyl 2 & 5 fire at the same time once Cyl 2 & 5 fire together once more Cyl 1 & 6 fire at the same time once Then the cycle repeats. I have no idea why 2 & 5 fire twice consecutively but this is my first inline 6 engine so maybe that's just how a straight six fires? I can upload the slowmo vid if anyone is curious. I could also hear all the injectors ticking away but I had pulled the fuel pump 10A fuse so I don't flood the motor. Then we tried taking the 3 CAS bolts out and manually rotating it outside of its factory range, to see if we can get the timing closer to 10 BTDC (stock for 20neo). If we rotated the CAS clockwise (ignition RETARD) maybe a good 20-30 degrees outside of its normal range, and if I input "-10" on crank advance degrees within AEMTuner, we got close to 5 degrees retarded of TDC. But this still isn't good since the CAS could not be bolted on properly. Tomorrow we will experiment a bit more with this. Also we were using an old spark plug wire fed into the #1 coil and then going to #1 spark plug, with the timing light sensor hooked onto it as I know this is a more accurate way of measuring instead of at the blue loop at the back of the ignition loom.

WMDC, the harness that was given to me for comparison was off a 1997 spec 2 gts4t poor man's GTR. I've made the pins correspond to a spec 2 wiring schematic while retaining all of the Neo features including the swapped Neo CAS wires. The 120 deg (cam) and 1 deg (crank) signal wires go to pins 41+51 and 42+52 respectively. I've mentioned this before in another thread but I also had to adapt an RB25DET Neo Gloria engine harness to fit all this, and that one came without the ECCS relay next to the ECU like it is on a spec 2 harness, so I had to wire in a relay like that following the spec 2 diagram from that nice R33 schematic that can be found here. GTSBoy, it may have an oscilloscope built in but at this point I am still getting to grips with it and figuring it out. It does show me cam/crank pulses in miliseconds, sync, tooth errors and all that. I've done a big 3 upgrade on the wiring and I'm certain this car has great power and ground, have also tested for electrical leaks and it's as clean as a whistle. All my joints were soldered, heat shrunk etc, no expenses spared. I have verified that the motor is at TDC when crank pulley reads 0 (first mark). I also turned the cas by hand and it triggers the fuel pump and spark. In fact by hand trying to spin it, i am triggering those events much quicker than by cranking (logical I know). I got to a dead end today (AGAIN!) and ended up calling one of the more renown tuners from my country who has experience with AEM and some nissan motors. He was very helpful and dedicated an entire hour remotely connecting to my laptop and messing around with the settings. The closest we could get the timing synced was 5 deg retarded. 1 degree more than that, and the timing light started showing 60 degrees ADVANCED which made no hecking sense! He said if he kept trying he might be able to get it to run but highly recommended I make my own trigger wheel replica of AEM's and try using it. So I just drew one up on Solidworks and tomorrow I will look for the right material because the stock neo disc is I shit you not, 0.13mm thick! I think anything more than 0.2mm and it may hit the sensor head. Also I will try running direct 12v to the ECCS relay and see if I get stronger spark and fuel when cranking just to rule out the relay or wiring. I will keep reporting back but in the meantime if anybody has more ideas I'm all ears.

Heya people from down under, As the title states, my project is at a point where I finally could crank the motor over to attempt a first start. I'm running an AEM Series 2 standalone ECU with a 33 connector which I repinned myself, car originally was spec 2 but the motor I put in was an RB20DE Neo from an R34. I've configured it to run via Speed Density using an AEM 3.5 bar MAP and IAT sensor. It's using the stock Neo coils and the stock Neo Hitachi plastic top CAS (360 slots for crank and 6 slots for cam ref). I have made extra certain that my re-wire and custom wiring suited the Neo but also copied a spec 2 harness which was given to me to compare against. I have double triple checked all the sensors and wiring which go to the ECU etc and they all follow the required inputs for the AEM ECU as per their pinout. For the last 4 days I have been trying to start this motor with no success. I have amazing oil pressure, the walbro 255 primes and turns on while cranking, I get 3 bar of pressure at the regulator. I also checked #1 coil for spark, it does spark albeit slightly weak looking and orange in color (as opposed to bright white/blue). We also noticed that the injectors (R35 GTR 570cc) don't seem to be opening. I tried using a spare injector outside using brake cleaner through it and having it plugged into the loom, the motor cranks but the injector doesn't open. We've probably cranked it over 100 times by now (bad I know!) and the cylinders aren't even remotely flooded, mostly dry. That said, I suspect it's an issue with spark and fuel altogether. The AEM EMS setup wizard has an option for "Stock RB 6 cylinder CAS wheel" as well as an option for "Stock R33/R34 Series 2 coils" both of which I have enabled and it apparently automatically sets the required dwell times and syncs. I do get a "CAS SYNC ON" status while cranking and I do get engine RPM signal (up to 400 or thereabout) so I know the eCU is receiving those signals from the CAS. BUt the timing is completely whack. With a timing light, with no adjustment of the electrical timing, and CAS set at the middle point, using a good timing light, the crank marks appear nearlt 60 degrees retarded. And even if I max out the crank advance setting (+73deg) and lock the base timing at 10 BTDC, the timing light still only gets to about 15 deg advanced of the 0 point on the crank. Basically it's erratic and not stable. I was very careful when timing the motor and turned it over by hand a few times to double check everything lined up. Also the motor cranks extremely well, fast and strong. No banging or screeching or huffing. She's thirsting to fire but cannot for some reason. I've got experience tuning my Mitsubishi with another tuning platform but this AEM is kind of overwhelming and I fear I need some help. If anybody has an idea or pointers at what I could look at, please I would be super appreciative! I could also provide screenshots of the advanced pickups tab or anything else.

You are very polite, we are having a technical discussion like adults and I don't see a problem, compared to some other forums I've browsed through before. I'm not trying to argue for the sake of it or make it seem like I'm a know-it-all, but I believe I've got a good understanding of automotive fuel systems in general so that is why I'm standing by my explanation. One key factor I forgot to mention is related to safety. In the event of a roll-over, fuel can go up through lines it shouldn't, such as the fuel filler and vent hose. We all know fuel fillers are required to also have a one-way check ball or flap, such as the one that flaps inward when we insert the fuel gun. Likewise, the venting system also requires such a safety mechanism because when you think about it, that vent line most always goes at the very bottom of the car until it reaches the engine bay, which then goes into the charcoal canister. So for the most part, its location is lower than the highest part of the fuel tank. Fuel can and will fill that line in the event of a roll-over, which is another reason why there would be a check valve before or after the canister for this very reason. The least somebody could do after removing the canister entirely is to keep a check valve at the end. In motorsports this is a mandatory requirement as well as a strong check-ball in the fuel filler neck if one is fitted to the fuel cell. On my Mitsubishi I've had the canister removed since 2016 and have ran the factory valve at the end of the purge line like that, venting under the wheel well. My reservoir has not caved inward, or split, or blown apart. My fuel pump runs great and maintains adequate pressure. The gas cap produces a hiss when unscrewed which is normal. And I do not get strong fresh fuel odors around the engine bay or car for that matter, and I can pump fuel in quick without it going up the filler neck. P.S I never stated that the fuel tank should not be vented or that it is completely sealed. In fact I said the opposite. Having a check valve with a low cracking pressure at the end of the vent line does not make it permanently sealed. While filling up fuel the air can be pushed out through the existing vent on the fuel filler neck and through the check valve on the purge line.

Okay so let's get technical here, I guess my degree in automotive engineering might come in useful after all. The fuel system in your average car is quite simple. There is a fuel tank, a fuel pump, a line and the fuel rail. We wont focus on things like regulators and injectors. The fuel tank is a sealed unit however it is not under perfect vacuum. At any one time there is both fuel inside as well as air mixed with fuel vapors. As the pump runs, it constantly sucks fuel out of the tank and pushes it to the rail. Any excess fuel is returned via the return line back into the tank. The less fuel there is, the more fuel vapors develop. And the longer they sit inside especially during warm summer days, the more chance they have to start pressurizing but UP TO A POINT. Usually, they cannot go past the fuel pump because the pump is already filled with fuel and usually has an internal check valve which is there to keep it primed at all times. The vapors also cannot go back through the fuel return line because at the end of it sits the regulator diaphragm. So the only way for the vapors to escape is through your gas cap OR any emissions system such as the charcoal canister. The charcoal canister is an emissions system which manufacturers were made to start adding to their cars. The goal is to capture the hydrocarbon vapors emitted from the fresh fuel sitting in the tank. Before that, the system was much simpler with either just a regular open end hose right off the reservoir venting to atmosphere, or if your car was fancy you'd have a small fuel filter and/or check valve. Again, the effect was the same; at a certain pressure the valve would crack open and release the built up vapor pressure. An important thing to note, the pressures that can form inside are very small, usually less than half a psi. Your analogy with the jerry can does not work here because we aren't relying on gravity to help the fuel leave the canister. We are relying on a positive-pressure pump to produce the flow to the rail, and since these cars use a return system, fuel is constantly in circulation also aided by the venturi effect in some fuel tank setups.

It's not so much there to keep dirt from entering, I'm aware it has a minimal impact (although grime buildup is still something to be considered in damp/dusty environments! The factory set up has a check valve in-line before or sometimes after the charcoal canister on like 99% of road cars. What I was suggesting to OP was, if he has trouble finding the OEM setup or if he does not want to clutter up his engine bay, the easiest and cheapest way to cure his strong fumes problem is to retain (or add) this check valve. If he lets the line vent freely he will continue to get strong whiffs of fuel. Adding the valve keeps them inside the fuel tank where they're meant to stay. And in the events of over-pressurization, both the check valve and the gas cap can do their jobs and vent it out. But he would have opened his cap to refuel way before such an event occurs anyway.

It's a one way valve, it lets stuff one way but not the other. So if you have it set up with flow from reservoir to outside air, then have another foot of hose after it venting to atmosphere, neither dirt or water can get through it and into the lines. But in-tank fuel vapor can still exit through that check valve if it gets too high. The other valve I mentioned is built into the fuel filler cap. That also has safety mechanism which will let off vapors if they get too pressurized for whatever reason.