PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

STFT's still active in open loop?

Old Jun 18, 2005 | 10:59 PM
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Default STFT's still active in open loop?

I was preparing a logging run using widebands with the commanded AFR / actual AFR method. I did the following to prepare as has been recommended:

Disable LTFT's
Raise DFCO speed to 255 to disable
Raise closed loop temp to 255 to disable
Car is already in speed density mode.

I noticed that during the logging run, STFT's are still active. Are they still affecting A/F in open loop, or just innocently flipping numbers. If they're still affecting the mixture, is there a way to shut them off altogether? Perhaps I missed something simple.

Thanks
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Old Jun 21, 2005 | 11:04 AM
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bump^^^
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Old Jun 21, 2005 | 11:39 AM
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are you running a cutom os
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Old Jun 21, 2005 | 12:14 PM
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read the writeup on hptuners website under v8 tuning. step by step.
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Old Jun 21, 2005 | 12:53 PM
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Originally Posted by mistermike
I was preparing a logging run using widebands with the commanded AFR / actual AFR method. I did the following to prepare as has been recommended:

Disable LTFT's
Raise DFCO speed to 255 to disable
Raise closed loop temp to 255 to disable
Car is already in speed density mode.

I noticed that during the logging run, STFT's are still active. Are they still affecting A/F in open loop, or just innocently flipping numbers. If they're still affecting the mixture, is there a way to shut them off altogether? Perhaps I missed something simple.

Thanks
What method did you use to put the PCM in SD mode? Did you turn off DTC p0103?

You should not be getting any fuel triming in open loop, as the PCM doesn't use O2 sensor feedback when in this mode.
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Old Jun 21, 2005 | 05:44 PM
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Thanks everyone for the response. I'll try to answer everyone's questions is one gulp.
Yes. I'm running a custom OS that keeps both spark maps in SD mode. All of the appropriate MIL's have been disabled. I put it in open loop by raising the enable temp all the way, but the STFT's persist. There are plenty of other STFT related parameters under the O2 section, but I'm not familiar with what their effect is, so I'll wait for more detailed advice and/or smarten up a bit. I'll definitely check out the thread over at HPT and report back.
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