Nistune messing up over 3k rpm

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jeeta_s
240sx Wannabe
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Nistune messing up over 3k rpm

Post by jeeta_s »

So i had my car professionally tuned with nistune by a very reputable guy in my area, however for some reason after about 1 season it began to act weird. For instance, when i hit 3k rpm in 5th gear my afr is at like 10, and it stays there until i come back under 3k rpm. Does that mean the ECU is jumping into safe mode and just dumping a **** load of fuel? I just would like to get an understanding of this before i take it to the guy, any help would be much appreciated.
thegr8one013
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Re: Nistune messing up over 3k rpm

Post by thegr8one013 »

theres a chance you have a boost leak and when when the turbo is spooling all that excess fuel is meant for the boost which your not getting
jeeta_s
240sx Wannabe
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Re: Nistune messing up over 3k rpm

Post by jeeta_s »

OK maybe I should start there. Thanks for the quick reply. Only thing is that it wouldn't completely account for running rich past 3k in fifth cause I'm not not trying to hit boost (I.e. just cruising)
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supakat
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Re: Nistune messing up over 3k rpm

Post by supakat »

Regardless, boost leak test it. Simple to do and answers a lot of questions.
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ridin4life
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Re: Nistune messing up over 3k rpm

Post by ridin4life »

these cars have a 5th gear sensor which stock ecu has a separate map for 5th gear. I don't know if its removed on the nistune or if the 5th gear map is still there. might want to look around nistune and see if the 5th gear map still exists.
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airman
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Re: Nistune messing up over 3k rpm

Post by airman »

^ I don't believe there is a secondary map for 5th gear. There is a normal map and a knock map. I am pretty sure the 5th gear sensor is just for speed limiting - at least in S13 ECUs.

3k RPM in 5th - is that under boost, or just cruising?

Rich in cruise could be a lot different than rich in boost when it comes to finding the problem/a solution.
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