Jump to content
SAU Community

Recommended Posts

Hi Guys

I Have got 740cc Injectors to go into my rb25 and i was wondering if there is anything that ill NEED to do other than fit them to make them work

Can i just Install them and drive away or is it a case of i need to do something else cause the ECU wont read them etc etc

They are actually Highflowed Injectors so technically there still stock just bigger holes....sort of.. LoL

Any help would be much appreciated if im on the right track of needed more than just to install

Link to comment
https://www.sau.com.au/forums/topic/352142-rb25det-740cc-injector-upgrade/
Share on other sites

the injectors will foul and flood the engine of fuel unless you tune for the size.

speak to your tuner about it. You may also need a bigger fuel pump if the one you have isnt flowing enough.

Then the direct 12v of power, the other RB Guys should hep u with this

Edited by AaronNM35

Since you're doubling the size of the injector, you'll be injecting about double the amount of fuel - my guess is it wont even run that rich. With a programmable ECU you just use the injector resize function and it changes the signal it sends to the injector to compensate for the change. You then need to check and probably fine tune.

as people have said, with the stock ecu it can't be done. if you have an aftermarket ecu then it is easily done. fitting is a bit of a pain in the arse though. as for as what else you need, a new set of O-rings for the injectors is about it.

  • 2 months later...

Im currently trying to do the same upgrade, but im having trouble fitting them.

The problem i have is that the fuel rail i have (Greddy 11mm top feed) doesnt seem to fit with the standard intake plenum,

Does anyone know if there is a top feed fuel rail that will fit under the plenum with 700cc injectors? and if so, where can i get one?

Or is it not possible to fit a top feed fuel rail with the standard plenum :glare:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • The final part arrived today to un-clampify and simplify the intake Who would have though a 1/2" hose stainless bulkhead fitting designed for below waterline bilge pumps would be what I needed Test fit on a 3" offcut I had laying around to see if it would work, and it worked a treat All going well the intake will be on its "final version" tomorrow 
    • Good luck on the weekend mate
    • Must have been an absolute nightmare to drive when the power steer was out, the rack ratio/wheel size/caster is all set up for power assistance
    • Welcome to SAU, what are you looking at buying?
    • I checked the injectors again (1 and 2, since they’re easiest to access) to make sure they weren’t clogged. Even though the entire fuel system had been cleaned, I wanted to be certain. Everything looked clean, so I reinstalled and connected everything. When I started the car to confirm everything was okay, it immediately revved up high, so I shut it off straight away. I checked to see if I’d missed a vacuum hose or something, but everything was connected. On the second attempt, the car ran without the high idle, but I noticed a distinct “compressed air” sound coming from the engine bay. Tracing the sound, I pushed injector #6 forward slightly and the noise stopped — it turned out it wasn’t seated properly, despite the fuel rail being bolted down. While holding it in place, the car idled steadily without stalling and ran for over 5 minutes. At this point, I pulled all six injectors out just in case I hadn’t seated them correctly or dirt had gotten onto the O-rings. Unfortunately, I discovered that I had damaged 3 out of 6 injectors (the OEM 270cc ones) during installation. So yes, this was my fault. Since only the pintle caps were damaged, I’ve ordered a Fuel Injector Service Kit from NZEFI to refurbish them. In the meantime, I reinstalled my new injectors – the car now idles fine for over 15 minutes without stalling. I have not attempted to drive it so far. It’s not perfect yet, as it hesitates when the throttle is pressed, but it’s a big improvement. Unplugging the IACV with the new injectors idles at around 800rpm, even with the IACV screw tightened fully. But this is probably due to tune.
×
×
  • Create New...