Help interpreting LTFT+STFT MAF data
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Teching In
Joined: Sep 2007
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Help interpreting LTFT+STFT MAF data I recently got a 4L80E behind the 6 liter in my '66 LandCruiser (along with a lot of other stuff). The guy that did the install had his friend with GM equipment rewrite the ECM to a silverado and then make enough adjustments so that it would run, shift, and more or less idle. I have no idea what they did and now I'm trying to clean up. And I'm new to HP Tuners.
So, following great instructions elsewhere on ls1tech, I set up a graph of LTFT+STFT against MAF HZ. I included a scan with some data, I wasn't able to get into the throttle very much, but it was a 30 minute drive. I had previously used a short run to 'fix' 2000 to 2850 and I can see that it improved.
But I'm not sure how to interpret the value in 3250, 3375, and 3500 of the scan. They are hit during idle and I think they are related to some issue with idle. So, before I paste special all that into my MAF, I wanted to get some input.
I've also put the program file as well. Anyone with any input about the tune I got saddled with, I'd love to hear it.
Peter
So, following great instructions elsewhere on ls1tech, I set up a graph of LTFT+STFT against MAF HZ. I included a scan with some data, I wasn't able to get into the throttle very much, but it was a 30 minute drive. I had previously used a short run to 'fix' 2000 to 2850 and I can see that it improved.
But I'm not sure how to interpret the value in 3250, 3375, and 3500 of the scan. They are hit during idle and I think they are related to some issue with idle. So, before I paste special all that into my MAF, I wanted to get some input.
I've also put the program file as well. Anyone with any input about the tune I got saddled with, I'd love to hear it.
Peter
