Need help with idle surge/hunt tune and log attached.
#1
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Need help with idle surge/hunt tune and log attached.
I attached the tune and idle log, idle surges up and down a little in park and neutral but when you but it in gear it really hunts up and down.
E85
127lb injectors
390
4000 stall 4L80
the wideband is ngk and only has the gas scale, that's why it looks like it has gas afr's.
Thank You
E85
127lb injectors
390
4000 stall 4L80
the wideband is ngk and only has the gas scale, that's why it looks like it has gas afr's.
Thank You
#2
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* Start off by setting your idle ignition advance to mid 20s.
* Make sure your idle>in drive and idle>in park tables match and that they also match your high octane table up to 1,200 rpm or so. Needs to blend seamlessly from idle tables to high octane table. Your huge step from 19° to 30° between 800 and 1,200 rpm in the idle tables is probably causing most of the problem. Get those 19° tables up 6 or 7 degrees and blend into the high octane table.
* Idle Underspeed Spark vs RPM Error is too aggressive. Take out half or more in the -25 to -250 fields.
* Idle Overspeed Spark vs RPM Error is better but could be reduced a little from 50 to 200.
* Injector Flow Rate vs KPA VAC - set at 127 all the way across... Do you have a boost referenced fuel regulator?
* How comfortable are you with the injector flow data?
* I'm a little suprised to see you don't carry the PE table out past 3,600 rpm. Even with an enhanced OS boost table most folks set the PE table and use the boost table as a backup. The way I understand it is slower to react than the PE table.
*Base Running Airflow>Idle Airflow - I assume you have scanned and set this table appropriately?
* Primary VE - What's up with all the peaks and valleys? Lot's of room for improvement with some smoothing.
Maybe some of these comments will help with your idle surge. I typically work on smooth ignition idle tables and then look at idle airflow.
* Make sure your idle>in drive and idle>in park tables match and that they also match your high octane table up to 1,200 rpm or so. Needs to blend seamlessly from idle tables to high octane table. Your huge step from 19° to 30° between 800 and 1,200 rpm in the idle tables is probably causing most of the problem. Get those 19° tables up 6 or 7 degrees and blend into the high octane table.
* Idle Underspeed Spark vs RPM Error is too aggressive. Take out half or more in the -25 to -250 fields.
* Idle Overspeed Spark vs RPM Error is better but could be reduced a little from 50 to 200.
* Injector Flow Rate vs KPA VAC - set at 127 all the way across... Do you have a boost referenced fuel regulator?
* How comfortable are you with the injector flow data?
* I'm a little suprised to see you don't carry the PE table out past 3,600 rpm. Even with an enhanced OS boost table most folks set the PE table and use the boost table as a backup. The way I understand it is slower to react than the PE table.
*Base Running Airflow>Idle Airflow - I assume you have scanned and set this table appropriately?
* Primary VE - What's up with all the peaks and valleys? Lot's of room for improvement with some smoothing.
Maybe some of these comments will help with your idle surge. I typically work on smooth ignition idle tables and then look at idle airflow.
#6
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How do you run your reference line? Check valve? I've noticed since the switch to E85 that it seems to react different to the underspeed and overspeed timing. I ended up chasing my tail.
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