Super lean issue

Nistune topics specific to the 6802 cpu

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rsfire
 

Posts: 14
Joined: Thu Jan 09, 2014 8:01 pm
Location: Roseburg, OR

Super lean issue

Post by rsfire »

So yesterday when I went to drive my car in the morning it would barely move, it would just run full lean and die. I got in from work the night before and it had been driving perfect, as it has been for awhile. I haven't touched a thing before it started this issue.

I tried loading several different tunes and sometimes it's exactly the same and sometimes it runs well for a minute or two then just goes lean. The last test drive it ran in the 15s and 16s while cruising for awhile, but I went up into light boost several times and it just goes into the 16s by 0psi then 18+ beyond that and loses it's power. I'll attach some logs of that. Toward the end of the drive it was just running past 18 on my wideband until I got home. I'm completely stumped unless my ecu went out. Any ideas?

I have attached two logs and my tune, thanks!!
Attachments
5-23 tune.bin
(16 KiB) Downloaded 137 times
NIStune_2014-05-23_1647_58.csv
(298.16 KiB) Downloaded 148 times
NIStune_2014-05-23_1653_01.csv
(126.4 KiB) Downloaded 162 times
Ben C
 

Posts: 13
Joined: Sat Mar 23, 2013 9:09 pm
Location: Adelaide

Re: Super lean issue

Post by Ben C »

Check fuel pressure. It's unlikely the existing just stuffed up.
rsfire
 

Posts: 14
Joined: Thu Jan 09, 2014 8:01 pm
Location: Roseburg, OR

Re: Super lean issue

Post by rsfire »

Yeah that was first thought, I checked my fuel pressure and it's 37 idle and up around 40 revving, but I'm not sure what it does while driving.
rsfire
 

Posts: 14
Joined: Thu Jan 09, 2014 8:01 pm
Location: Roseburg, OR

Re: Super lean issue

Post by rsfire »

More info- so i tested out my original 86T ecu and it works fine for the most part so far. So I'm assuming something is wrong with my nistuned ecu and not the cae, i have no idea what to look into for fixing it.
Matt
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Re: Super lean issue

Post by Matt »

Look at the log. AFRs are all over the place even though injection time, RPM and MAF are consistent. Something outside of the ECU
Attachments
z31_19P12.png
(72.61 KiB) Downloaded 2567 times
rsfire
 

Posts: 14
Joined: Thu Jan 09, 2014 8:01 pm
Location: Roseburg, OR

Re: Super lean issue

Post by rsfire »

Hmm do you think the injectors would be my best bet, if they're getting the signal from the ecu but just not opening how they should? Do you have any thoughts?

And i did switch to my stock ecu and it runs rich, like 12 to 13ish AFR while cruising(i have no o2 sensor if that causes that) but under full load it gets up to 12.5 at 12psi. Even though cruising is too rich it runs well and consistent.
Any ideas why that ecu would work but not my nistuned one?
Matt
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Re: Super lean issue

Post by Matt »

Injectors/MAF used?
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