R32 GTS (RB20DE) Injectors Replacement

[GabsReDeal]

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/

 

[Murray_Calavera]

First thought, have your current injectors flow tested. If they test fine, keep the diagnostics going. It's not the injectors.

If the injectors are the issue, find some new or used (cleaned and flow tested) injectors. 

While I really love a good excuse to get a modern ECU installed, just needing new injectors probably isn't a good enough reason to do so. 

[GTSBoy]

^This.

If you have to do injectors, and you have to buy bigger ones, get the smallest Bosch EV14 based injectors of the correct length that you can. This will be about 500-525cc most likely. The stock ECU (with Nistune) will be fine to run those.

Then, use a Nistune. Tune it yourself. If all that you are doing is changing injector size, then you literally only have to change one number to do it, and then maybe some fine tuning of that number. You will not need to touch the fuel or ignition maps at all.

[joshuaho96]

Nistune is pretty easy if all you want to do is change the injectors. TIM + latency change will do it. But I am very skeptical your mechanic has actually diagnosed the issue. As others have said flow/function test your injectors. 

[GabsReDeal]

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.

 

[joshuaho96]

8 hours ago, GabsReDeal said:

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.

 

Swap the injectors around and see what happens. If the misfire follows the injectors then that's a signal, if it doesn't it's probably not the injectors.

[GabsReDeal]

On 17/04/2025 at 10:03 AM, joshuaho96 said:

Swap the injectors around and see what happens. If the misfire follows the injectors then that's a signal, if it doesn't it's probably not the injectors.

That is what I will be doing next