Jump to content
SAU Community

Recommended Posts

Hi Forum goers!

I'm hoping to get some help on an issue I am having with my RB20DET.

When it was on the dyno it was found that the car is running dangerously lean when on boost. The A/F mixtures are not smooth either.

I have recently had the fuel pump changed to a higher flowing unit and the fuel lines, injector rail, injectors have all been cleaned. The people who did the fuel pump said that it was running lean so checked the fuel pressure and found that the fuel pressure was ok. They also said they checked the main sensors and found them to be in working order.

On the dyno I was lucky enough to be able to borrow a chipped ECU (thanks!). This ECU improved the mixtures and smoothed them out but the car was still running very lean.

I'm hoping someone can help give me a few suggestions on what to try or what to change.

Any help appreciated.

Thanks for reading!

Will...

Link to comment
https://www.sau.com.au/forums/topic/9921-help-engine-running-way-too-lean/
Share on other sites

Did you check the fuel filter when you did all the rest? Might be worth a look. Check the vacume/boost pipe going to the fuel reg, if it's blocked the fuel reg won't increase preasure while on boost.

Ummm..... You've checked everything else that I can think of.

Good luck

J

Check your Air Flow Meters if you have them, especially if you have pod filters. The oil from the pods can bake onto the Air Flow Meters which makes the car lean right out. Take the Air Flow Meter off and hit it with some Carby Cleaner then some contact cleaners. Refit and test again. It worked for me.

Mick.

The injectors have been cleaned (that's what I was told and have no reason to believe otherwise...)

Another AF meter was fitted and whilst this gave a slightly better mixture the car was still running lean so I'm guessing it's not the AF but a clean never hurt anything.

I haven't checked the pipe of the fuel reg. Can youpoint me in the right direction to this pipe?

Thanks for all the help at least things checked have been on the right track.

:)

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

    • I refreshed the OEM injectors with the kit and connected it up. It now ideals okay even with the IACV removed. Driving still has the same cutoff issue like the 550cc injectors so the issue is somewhere else. I bought FPG's Fuel Pump Hanger. I will be installing it next, but it is not as straightforward as I thought it was with my limited wiring knowledge and no instruction on the specific model I purchased (FPG-089). I also got the incorrect billet clamp as I could not find info on the OEM sizing.
    • Stop looking at the garage floor, and turn the radio up a bit louder if there's any strange noises...
    • No. Turbo shuffle and surge/flutter are not the same thing. Specifically, on a GTR, turbo shuffle has a definite meaning. On a GTR, the twin turbos are assumed to be the same thing and to operate the same way, exactly. In reality, they do not. Their exhaust sides are fed and exhaust a little differently, to each other. Their inlet sides are fed and exhausted a little differently, to each other. Consequently, when they are "working" they are often at slightly different points on the compressor map compared to each other. What this means, particularly when coming on boost, is that one of them will spool up and start producing extra flow compared to the other, which will put back pressure on that other compressor, which will push the operating point on that other compressor up (vertically). This will generally result in it bumping up against the surge line on the map, but even if it doesn't, it upsets the compressor and you get this surging shuffle back and forth between them That is "turbo shuffle" on a GTR. It is related to other flutter effects heard on other turbo systems, but it is a particular feature of the somewhat crappy outlet piping arrangement on RB26s. There are plenty of mods that have been attempted with varying levels of success. People have ground out and/or welded more material into the twin turbo pipe to try to prevent it. Extending the divider inside it works, removing material doesn't. There are aftermarket replacement twin turbo pipes available, and these exist pretty mush purely because of this shuffle problem.
    • You can temporarily* use lock collars to keep it in place until you can do the bushes, back the nuts off, slide them in, snug back up. *temporarily is often for ever
    • Thanks for the quick reply. To be clear, when you say turbo shuffle do you mean turbo flutter "stustustu" or referring to something else? I had thought they were the same thing. When I wrote the post my intention was to say it wasn't a flutter/compression surge sound. My understanding was that a flutter sound would be occurring when throttle is released, whereas I can keep the throttle in the same position for this noise
×
×
  • Create New...