97 confusions

[NewBoost1997]

So me and a friend are trying to tune my car. He has tuned many before and people like it. But here is an issue that he had posted on a different forum and he told me to post it here to see if anyone else knew. Here it is:


**Had a buddy come over today for a tune on his 3.4/headers etc setup. First off the negative spark values is strange (which Im aware of)

But after watching different pulls the WOT spark varies from -4* sometimes, to -14* not to mention his GFS table WOT spark is about 19*.. I zero'd out the AFR spark modifier, the AIT modifier, the TCS spark reduction...

Any have explanations? Its quite strange.. any help or discussion would be great. ***

[BillBoost37]

What does the LOS table read? There's high octane aka gfs good fuel spark.

[NewBoost1997]

Its been altered. BFS is stock. My GFS is an 04+ table.

[BillBoost37]

You didn't really answer the question though. I was asking if the low octane table had the timing you are seeing in the cells you are seeing it in. Meaning..maybe the pcm was using the low octane table. If you see too much KR to too long..it assumes you used crappy gas.

Have you reset and reflashed to ensure you are on the high octane table?

[NewBoost1997]

We reset and re flashed it a couple times. For each change we made we re flashed it. Is there another way around it or to ensure it uses the GFS table? I'm running 91 because that's all that's available where I'll be going to school for 10 months. When we made changes we made a couple runs getting 14* of spark with the GFS set at 19*. But a lot of the time we saw 5* spark and 11* of knock once I let off the throttle


Could a slight idle misfire/rough idle cause it to go into my
BFS table?