Adjusting The Idle Screw On The Aac (rb20det)

[ross80]

I would have though 700 rpm is a bit low for a rb25 to idle?

I could be wrong but my last two 33's have been around 900?

[RB30-POWER]

specs straight from the official nissan service manual!

[RB30-POWER]

gtr idle is 900rpm

[ross80]

Ok me bad then,

Could this be the reason after elliminating a lot of problems that my car hits a hessitating almost like a limiter of some sort at 5000rpm?

Any thoughts?

[ross80]

double post

[RB30-POWER]

Are you running more then standard boost on the standard ecu?

[insu]

Hey guys.

Hey RB30-POWER, where did you get the instructions for the resetting of the idle on the RB25DET? I only ask cause it was my DIY posted up on here to invloving my idle reset from when i cleaned my AAC valve.

I can't remember 100%, but i'm pretty sure I got my method from the nissan engine service manual.

I might have got it around the wrong way like you've posted and its the TPS sensor that needs to be removed while adjusting the idle through the idle adjustment screw, and not the AAC valve as is the method for the RB20det.

Either way, it seems to work i spose, as it is the AAC assembly that allows more air in for idle if it thinks the car needs it, and by disconnecting this plug while adjusting the base setting then re-attaching the connection and looking for any differences in idle speed before fine tuning if need be (though i still haven't heard of any skylines requiring this step).

The best reason I can think of for disconnecting the TPS from the RB25 while adjusting the idle screw, is so that the value coming from the TPS is absolutely nothing, so even if the car thinks it has to compensate for a TPS setting or that the Throttle is even partly open, it won't affect the setting of the idle.

Or I may be completely wrong.

Edited May 3, 2006 by insu

[insu]

Oh and don't worry if your idle tends to be a little bit higher, it seems that most skylines especially modified ones tend to idle happily around the 800rpm mark.

[insu]

Oh, I see from your post I missed RB-30 that you got your details from the nissan service manual, I might have to have a gander of this again, and fix up the errors in the DIY.