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Rb20 Stalling/ Running Rich?

GTEES

By GTEES,
in Engines & Forced Induction

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GTEES Proficient

GTEES

Posted
Posted

I apoligise if this has been covered, but i've done plenty of searching and can't find alot or matching circumstances to mine.

recently purchased a 32 gtst and I've noticed when warmed up and everytime i pull up it idle hunts very low (down to around 400rpm) and sometimes even stalls.

i've been told it's running rich, there is a lot of black build up inside and around the exhaust and it occasionaly pops on gear changes.

mods are:

-r34 turbo

-3inch turbo back exhaust

-nismo 555cc injectors

-z32 afm

-walbro fuel pump

-blitz return flow cooler (dent from tow bar, been told it still holds pressure fine)

-hks pod with CAI

-aftermarket cams

currently running on stock boost.

The car has had a tune done by Dr drift by the previous owner.

I don't have a whole lot of knowledge about forced induction as this is my first turbo car but i have a suspicion that the car was running higher boost before being sold as all these supporting mods seem fairly pointless at stock 5-7psi boost. If the car WAS running higher boost than stock and was tuned for the higher boost level with these mods, would this explain the car running very rich and almost stalling from getting too much fuel?

any help would be appreciated, thanks.

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GTSBoy Grand Master

GTSBoy

Posted
Posted (edited)

The wank off valve is a likely candidate.  In the absence of such a thing then....  

The answer for your specific question about the previous boost level and tune is...  

NO.  It won't have any effect unless it's completely f**ked.  Also, stock boost for R32 RB20 is 10 psi.  

And so, you should look into cleaning the throttlebody with carby cleaner and a rag (or 5 rags) and also clean the idle valve (take it off and soak it in carby cleaner/any other good solvent until the black shit stops falling out of it.  This might help.

Edited by GTSBoy
GTEES Proficient

GTEES

Posted
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Posted

yeah thought about cleaning the throttle body and idle valve, did this on my old NA and did get rid of idle hunting for a while.

forgot to mention oil pressure sits a bit low i think, where abouts on the stock guage should it be sitting under normal driving load?

kitto Mentor

kitto

Posted
Posted

Service it, plugs, oil, filter, air filter, clean up the coil packs do a major service such as water pump timing belt etc if its due for it.

Clean your throttle body, AAC valve, check to make sure the Idle Air Control Valve IACV is working properly. Its like a choke in reverse on an EFI motor, sits under the throttle body and controls the idle on cold warm up and the regulary fail. Although your symptom doesn't point to the IACV.

One you've done all of that and its still not running sweet, take it and get it retuned again by someone who really knows NIStune, if your in SA, get Garage 7 to tune it for you.

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