Diablosport Forums

Trinity Users:

I have a stock 2014 Corvette Z51 7 speed. Just started using Trinity to explore a noticeable rough idle. The idle is rough for both stock and Diablo 91 tune.

I see STFT varying at idle (+/- 20 rpm) as well O2 sensor voltages. My LTFT is around -9% on both banks.
I was thinking it was questionable 91 real gas causing the problem. In process of cycling through various gas stations and running logs.
Some other ideas to consider:

1) LTFT is low because I run Ecomode to/from lake. Maybe that has trained my LTFT to back off because of only 4 cylinders?
2) LTFT is low because the factory tune runs a little rich and the ECM is backing off?
3) LTFT is low because the engine is starved for air and a CAI or Meth injection may address that?

The ECM shows AFR is 14.7/1 across all loads.

Any suggestions or experience with this would be appreciated.
Thanks,
Vargas1

IMO the rough idle is normal for the LT1. Especially on a cold start.

Mike:

First off, the Diablo Trinity is a quite an empowerment tool! Not just horsepower. Thanks for making it.

I have run probably ten logs on my C7 and think I see where I fill up affects both my knock and possibly my idle.
A little touch of TORCO Accelerator seems to make quite a difference. (Higher octane).

Anyway, can you provide me a brief public education on how you would address a consistent -9% LTFT in both banks if one or more of these are true:

1) AFR is a stable 14.75 across all RPM.
2) The LT1 is direct injection and the LTFT are not adjustable via Trinity.
3) I don't know what I'm doing.
4) I don't need to worry about this because the ECM is doing what it's supposed to do. Don't worry, be happy.
5) If I add more oxygen, the injectors are already big enough to handle it and just make more power.

Thanks so much.

#4