GabsReDeal

After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4 Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained. At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.

Despite having minimal clothing because of the hot weather right now, I did have rubber gloves and safety glasses on just in-case for most of the time. Yes, I was scrubbing with my gloves on before, but brushing with a brush removes the remaining rust. To neutralize, I was thinking distilled water and baking soda, or do you think that would be overkill?

I found the ingredients at larger amounts from a Coffee Shop. 1kg Citric Acid for €8.50 500g Baking Soda for €2.50 I tried it out tonight distilled water (I got from my ACs) and dish soap. It does get bubbly with dish soap. In just two hours the hanger has improved significantly and rubbing against any remaining rust seems to flake it off. I'm going to leave it a little bit longer and see how it goes. I have read that someone even used this solution in an ultrasonic cleaner to clean a seized water pump which brought it back to life.

Thanks a lot for this, it does look promising. I imagine I'm going to need a lot of the solution for the tank to get fully clean (or I guess I could rotate it around especially since it does not lose its effectivity). I will see if I can get the ingredients to try this out with the hanger first.

That would really suck. I'll have to check that out as well. The older injectors did get clogged before changing the filter, but having them switched would obviously peed up the process greatly.

I haven't yet, but the fuel filter has only 2 months of usage on it (1800kms at most). But considering how the new injectors got very dirty in 3 days, I can only imagine what's inside the filter right now.

I removed the fuel pump to take a look at the tank. The sender unit is very rusty. Took a look at the tank and it is also quite rusty. Right at the base of where the fuel pump sits, there's a buildup of what seems to be rust particles. I did find new OEM fuel tank (17202-01U01) and sender unit (25060-01U00) from amayama which would set me back around €900 including shipping and customs. I most likely would need a new fuel pump as well. I'm going to be honest, I have been driving for around 6 years now and this is the only mechanic I went to apart for once (Last year I took my Porsche 924 to a guy who specializes on them). I've got a good relationship with him and he's always there to assist, even coming over to my garage at times for my convenience since the car was not starting. I believe he's got over 20 years of experience, but this is not the first time he let me a bit down on some basic diagnosing. I do not want to switch over to someone else, but I'd be lying if I said that it did not cross my mind.

That is what I have deduced, unfortunately. I had a suspicion that the fuel tank has a leak as I start smelling fuel when filling around half of it and can visibly see some liquid streaks. I imagine it was opened before, possibly previous owner suffered from this issue. I have asked my mechanic to investigate this when I took it to him before, but may have focused on the issue at hand instead.

On 12th June, the mechanic could not figure out what the issue was, but the car seems to be flooding with fuel. He was suspecting the tune, thus referred me to a tuner. Although the tuner is not familiar with Nistune, last Monday (30th June), he came over to try and re-map it. Despite the tuner trying to completely stop fuel, it kept sounding like it was pushing fuel. Tuner ended up suspecting either the ECU or Injectors. I do not believe the ECU or Nistune is the issue, as the Nistune software reads and communicates properly. Today, I removed the (new) injectors to see if they are clogged or leaking. Surprisingly enough, after those 3 days of driving, injectors 2 and 3 look very blocked. You can see the difference in the picture. I blew a bit on 3, that is why it doesn't look as clogged as 2. I am still unsure if this is what is causing the no start issue, but I am now feeling that I may have bought the injectors and Nistune without the need to do so, as the problem seems to be coming from somewhere else.

It seems that after 3 days of usage, it started missing again on one cylinder. Then eventually stopped missing but was stalling after a few minutes. The spark plugs, injectors, and fuel pump are all alright. So I am considering the tune might be wrong. Weirdly enough though, it took 3 days of running perfectly for it to start giving issues. Just an FYI, the fuel pump which is stock is constantly 3 Bar (43.5 psi). So you were absolutely spot on.

Yes I was planning to get it to a tuner with a dyno, but they told me to wait till September because the heat really started now and it is not ideal to do it in this heat.

It was gonna take much longer for the 440cc so I'd thought I'd risk it with the 550cc. They finally arrived and I couldn't wait any longer (I could but I was quite excited after 2 months) and installed them myself. Removed the old injectors, inserted the new and connected everything up. Before starting the car, I tuned the injector size from the factory 270cc to 550cc using Nistune. This did some of the calculations automatically which catered for the TIM. The latency however did not seem to change. Deatschwerks have the tuning data available for each injector online, and I had a look at it. It has a table which relates to latency according to pressure and voltage (see below image). Nistune requires the 14v value, but I am unsure of which pressure value to look at (my lack of knowledge and experience have something to do with this). The highlighted value is close to my current latency which is 760µs. It is for 14v which makes sense, and the pressure is 31.6 Psi. I still gave the car a test drive to see how it goes, and honestly it has never felt so powerful before (and some people say the RB20DE is very weak?). I really enjoyed the drive. Side note; The injectors are quite noisy, which someone mentioned before. This does not really bother me however. I will still ask my mechanic to have a look at it and perhaps ask a tuner to fine tune it if they have the knowledge.

They still have not shipped the 550cc injectors as they weren't in stock, so in theory I could ask to get the 440cc ones instead, if those work better in my scenario. They're the same price so really shouldn't be an issue. Unfortunately I am not so knowledgeable in most parts of tuning so I wasn't sure what's best to choose between the two. 440cc ones are the lowest they have (not in stock, but available to buy nonetheless).

Swapped the injectors around and the misfire followed. I went ahead and ordered the Deatschwerks 550cc injectors and am currently waiting for them to be ship and arrive. In the meantime, I've had my Nistune soldered to the ECU. Tested it, and and tried it out with the software. Everything should be prepared for when the injectors arrive.

That is what I will be doing next

Thank you all for you assistance. I contacted Nistune regarding the support for the RB20DE along with my ECU Code (23710-10U00). They do have a map for it and added the RB20DE as a purchasable option now as well. They also added Malta as a Billing and Delivery options as this was missing. I was honestly amazed at their quick response and action, it took less than 24 hours. I also looked again at direct fit options for injectors, just in case I were to replace them. DeatschWerks seem to use a Bosch EV14 base and makes ones that fit mine at 440cc lowest, but also have 550cc at the same price. I tried looking for other direct fit options and managed to find one (also Bosch EV14 based) which includes a plug and play adapter on ebay. Did a small test with a Noid Light on the troubled injectors and all seems good, so they are pulsing properly electrically. One weird part is that they are missing on the same two cylinders as before I got the injectors cleaned. Mechanic also found this weird as he did not label the injectors and it is unlikely to have the faulty injectors be installed in the same cylinders.

Back in January, I noticed my car felt noticeably weak. I had the injectors cleaned, which seemed to solve the problem -- until now. Recently, the car suddenly lost power again while driving. Suspecting the injectors, I brought it to the mechanic. He recommended replacing them entirely, saying the current ones were getting unreliable and fiddly to work with. I could not find a direct replacement for my current injectors. The closest match I found were 440cc injectors. This led me to look into the possibility of upgrading -- and of course, that would mean remapping the ECU. From my research I found: The OEM Part numbers are 16600-72L20 and 16600-72L21 Both the RB20DE and RB20DET use the same 270cc injectors. There are much better options out there over the old OEM injectors. Nistune could be a viable tuning option. While the RB20DE isn’t explicitly listed on their site, the ECU is essentially the same as the GTS-T version - just with a different map. The ECU code on mine is listed as supported. One concern is finding a tuner who works with Nistune. Aftermarket ECU like Haltech and Link, but this would be the most expensive choice (and possibly overkill for a mostly stock RB20DE) I admit that I am very new to the tuning scene and would appreciate any insight or recommendations regarding this. These are some SAU links where I got some of my information from for reference: https://www.sau.com.au/forums/topic/380324-rb20de-injectors/ https://www.sau.com.au/forums/topic/477396-factory-270cc-injectors/

I was told that they no longer fit high flow cats over here for some weird reason. But one exhaust shop said that they may have some old stock which they could fit if I wanted. However, I have other issues to handle at the moment and this is not a priority for now.

Small Update on the Exhaust Situation A 200-cell cat was a bit too expensive for now, so I had the exhaust shop fabricate a new exhaust from the cat to the rear and an exhaust tip. I went this route to avoid cutting into the original exhaust and keep it intact. It’s essentially straight-piped, and the sound is noticeably different. The exhaust tip came with a silencer, so if it gets too loud, I can easily install it to tone things down slightly. Right now, the car bangs and pops like crazy -- which I personally love. In the future, I might add a resonator or a 200-cell cat, as niZmO_Man suggested, but for now, I’m really happy with how it turned out.

Will ask the exhaust shop about this and get a quote if possible. My current pipe is with flanges and not welded on, so I can easily switch to my old cat if I wanted. I'd do it that way too. This shouldn't be an issue as long as there are no exhaust leaks afaik. Stock one was with flanges as well.

Just a quick update: I decided to go ahead with the de-cat for now. The exhaust shop inspected the catalytic converter and said it was in good condition. I took a look myself, and it does not appear broken nor clogged. After the de-cat, the car feels more responsive and smoother. The shop also reinstalled the exhaust temperature sensor into the de-cat pipe, and now the warning light no longer comes on, even when driving hard. The only thing that’s bugging me is the tinny, “can-like” sound the exhaust makes now (similar to having a hole in the muffler). The shop suggested that I might need to replace the muffler. I'll have to think on what to do next.

Yes shipping here can be a pain, was about to purchase timing belt replacement kit, but it tends to get expensive due to shipping (and customs if importing from non-EU which the UK now falls under).

Appreciate the feedback. It is street car, but not a daily. Last week I got a quote from a good exhaust shop for a decat, one which is bolt-on, bolt-off to be easily replaceable. I got quoted for around €150. I usually do push the motor, but I wasn't in this case to make sure that no damage is done until I get the cat sorted. I think it's best to also ask the exhaust shop for the other option and see what they can do. If (big if) I were to decat though, would it be best to tune the car or would the stock ECU handle it? As far as I know, the stock ECU is not tunable and that would require additional purchases.

Hey everyone, This is my first post apart of the introduction. I tried searching a bit on the forum but couldn't really get a straight answer. I got the car to my mechanic as I felt it being weak. It seems that it was missing on two cylinders due to the injectors. I had all my injectors clean and the car runs much better. The mechanic also confirmed my suspicions that the cat is clogged and needs to be tackled asap. The cat rattles a bit and the hot exhaust warning frequently lights up when driving after getting the injectors clean. In my introduction I was asked about what modification I might be interested in and mentioned a cat delete. From what I was told, this is not really beneficial on the RB20DE and there are more cons than pros. Could perhaps anyone give some suggestions on what the best course of action would be since the current cat is toast and needs to be removed/replaced anyway? I can also sometimes smell a strong smell of fuel, but I'm not sure if this is related.

We import a lot of cars from Japan. I'd say that approximately 20% of our traffic is imported JDM cars (mainly consumer cars like the Mazda Demio, Toyota Yaris, Honda Fit, Suzuki Swift, etc.). We also import a lot from the UK, but this has decreased after Brexit. Apart from the consumer vehicles, two of the larger, well-known dealerships frequently import iconic '80s/'90s JDM cars. I haven't heard of anyone importing from Australia, and they are not advertised (unlike Japanese ones), despite a lot of Maltese migrating to Australia in the '50s and '60s.