1998 C5 Corvette STFT Disable

[Allen C5]

Hello all,

I have tried a search for this, but all the info is very diluted and does not point to the answer I am looking for.

I am working on my 1998 C5 Corvette. I have installed a CAM and am in the process of tuning. I am trying to tune the MAF first, and have had no issue disabling the LTFT. All the posts I can find say to just toggle the "disable STFT" under Fuel > Open Loop, however I have no such dropdown option. It is missing altogether. With this option missing how can I shut down the STFT?

Thanks in advance,

Allen

[gtstorey]

Post the tune.

Are you looking in advanced mode?

[Allen C5]

Vett 2nd Try NO LTFT more fueling.hpt

I am checking on the advanced mode.

[Allen C5]

I checked on the advance mode. I am currently in it.

[blindsquirrel]

Is STFT actually still active in open loop, or are you just looking for a setting somebody said you were supposed to change?

[Allen C5]

Blindsquirrel,

When I am scanning I can see the STFT bouncing around so I assume they are still active.

[2xLS1]

The option to turn off STFTs is not available on 97-98 Vette or 98 F-body calibrations. You could try turning off fuel trim learn in the scanner bi-directional controls but that might just disable the LTFTs. I haven't tried that.

[Alvin]

There is usually a ECT qualifier for open loop. Set it to something high.

Some, but mostly trucks will use STFT in OL. Typically there is a drop down to disable/enable it.

[2xLS1]

There is usually a ECT qualifier for open loop. Set it to something high.

Some, but mostly trucks will use STFT in OL. Typically there is a drop down to disable/enable it.

Yes but STFTs can still be active in open loop. I'm not sure how the PCM does that but the later calibrations have the STFT Openloop Enable/Disable switch. the 97-98s do not.

[Alvin]

Yes but STFTs can still be active in open loop. I'm not sure how the PCM does that but the later calibrations have the STFT Openloop Enable/Disable switch. the 97-98s do not.

I've not seen STFT still working with them set STFT OL disabled.