Jump to content
SAU Community

Recommended Posts

In fact with a bit of squeezing with long nose pliers its possible to shut of all possible leaks from the other air chamber feeds. On the front side (does that make sense) you have two feeds to the blow off valves and the carbon canister. On the rear side there is a single vacuum line that feeds the brake booster.

In my case blocking all these off made no difference to the idle speed. So my problem is not an air bypass system issue. However, I only replaced the two throttle body gaskets but not the intake manifold gasket as that would have involved removing the associated water cooling components as well. That’s the only other place that I could imagine there may be an air bypass style leak occurring.

I have an aftermarket fuel regulator on the car which I no nothing about. In fact I’m not sure what impact that could have on idle speed. Does any one know?

Other than that I might flick the air flow meters for a spare set just to see if that makes a difference ( although the consult shows it shouldn’t :kiss:

so does this only affect R32 GTR? My R33 GTR also idles about 1100 RPM. It has only done this since getting it home and servicing it. It didn't originally do i when i first picked the car up - it sat at 900 then. It has a common issue with RB26s.

according to the underbonnet destructions, its supposed to idle at 650rpm. i've yet to see one that does. anyone? bueller? bueller?

mine runs at 1000rpm, but as i only idle at traffic lights, and everything else works - why worry? i aint gonna spend $1000 or more to fix a fast idle.

and yes, all gaskets are sweet, no air leaks (i replaced every external gasket once she landed on our shores) - although i'd be reluctant to pour water on a warm manifold -max 5 mins after startup for that trick.

The R32 GTR’s are supposed to idle at 950rpm. If the AAC is working correctly this will be the lowest the factory EPROM will allow it to idle. The work shop manual states that to set idle correctly, the AAC solenoid should be unplugged (or disabled via consult) and the idle speed should be set via the AAC idle adjustment screw to 900rpm. I guess this ensures the AAC solenoid regulates idle at the EPROM determined 950rpm. Of course if there is an issue such as a vacuum leak and the idle is artificially held above 950rpm then the ECU has no control (via the AAC) to regulate the idle. . If you have a consult program you can observe the AAC percentage vary to hold the idle at 950 rpm. Of course this only occurs at idle and only if the TPS idle switch point activates and provides the idle flag to the ECU. Again the consult will show the idle flag activate, followed by the AAC valve working to hold 950 rpm.

Edited by ADM

Hi cowie165

I use NissanDataScan v1.5 which I purchased for $30, not sure about the free/demoware options. Although for only $30 you might aswell purchase the real thing.

http://home.curl.aunz.net/tpkolo/DataScan.htm

http://www.plmsdevelopments.com/consult_if.shtml

  • 3 years later...

hey guys, i have a R34 GTT, it was sitting on 900 rpms, now after i changed the spark plugs to platinum, its idleing at 1100rpm, may sound stupid but maybe its the spark plugs or coil packs? im new to the car scene so please dont blast.

  • 2 months later...

I had a hunt at idle in my R32 GT-R. The highly technical solution was to adjust the screw on the front of the AAC valve, ie turn it clockwise to lower the idle speed, turn it anti clockwise to raise it. The hunt went away & it now idles at the setting the ECU tells it to. Which is about 1100rpm for a power FC.

Basically the valve does two things: Allows more air in for a cold idle. Controls the air (hence the idle speed when the engine is warm. It is buried under the inlet manifold next to cylinder 4 or thereabouts.

If the motor is hunting it is usually that it is getting too much air for the desired idle speed as programmed into the ECU.

Edited by djr81

Cant you just adjust the idling? Thats what I saw a mechanic did to mine (adjust it down to 950) but when I brought it to the tuner, he put it back up to 1100. Dont know why. I didnt have any problem with the car when I was at 950 too.

hmm....i alrady check my AAC is working ok, already closed the vacuums of the AAC and the air regulator, so its not there, i am thinking it could be the timing? because i remember before i removed my CAS, after installing i didn't use a timing light, and also my injector 6 is leaking, could be the cause?

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

    • Don't even try to run it on the stock ECU if you're going to have the boost controller bring boost above ~10 psi. I've already told you that. If you use the Nistune ECU, you will need to CAREFULLY read the available documentation for Neo tuning, and read some threads on the Nistune forums, to discover the various things you have to do to prevent the ECU from going bananas when the boost is too high. The is a table associated with th boost sensor that must be modified to prevent it from shitting the bed. This is just one of the things that you will need to do to the tune in Nistune, because the Neo turbo ECU will be expecting to see a number of things (such as the TCS) that are not there, and you have to block the DTCs on those. It is totally not surprising to me that you are having the problems that you are, but the solutions to these problems have been known for >15 years. So just get it done.
    • Hi. Sry iam not a mechanic and iam not at the car atm so i dont know 100% but they told they measure those and even try to change those. AFM they have two. Coils are new a they have my old one too. Plugs too. ECU...we have 25 NEO stock and Nistune 25 NEO.   But i dont know if any one those could be the problem and why/if/what can cause this, Only thing they did not check is fuel...but that walbro 255 is new(like 1,5 years)... That fuel pressure gauge idk...but i let them know Any suggestions?   EDIT: how can they know if it is like you say he ECU pull power when it reaches a specific boost level that is too high? Tha car has boost controler
    • Can you clarify what you mean by boost cut, do you mean it misfires both when under load (driving) and when stationary and out of gear? Or does the ECU pull power when it reaches a specific boost level that is too high (boost control issue)? Does it occur at idle with no throttle? When you say "the ECU is OK", what ECU is it and why do you think it is OK? Have you used the NEO ECU, and if so do you have a MAP sensor attached? Same for the AFM, why do you think it is OK? Do you have any way to put a fuel pressure gauge on it (even just a mechanical one between the fuel filter and fuel rail)?
    • Hi.. Just another problem. So maybe you can help. I(my mechanic) done swap from my RB20DE NEO to RB25DET NEO. Everything is OK but we have a boost cut. Coils/Plugs are ok...AFM is ok. ECU is ok. I have Walbro 255 but it "changed" sound few months ago(you can hear it ouside) you did not hear that when it was new(maybe faulty?) Sooo...what now? What can cause this boost cut? It is even when you standing still...
×
×
  • Create New...