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trying first SD tune, surging/sputtering horribly...

Old 11-25-2005, 08:01 AM
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Default trying first SD tune, surging/sputtering horribly...

I set the P0103 to set MIL at first instance and walked through the HPTuners wideband tuning help file. The SES light showed on the dash this time (if you read my last post).

I have to pedal the car to even keep it running/idling with the MAF unplugged, and it's fighting for all it's worth sputtering and surging. If I let off the gas it will sputter to keep running and sometimes dies. Is this normal for my mods (or normal at all ?). Should I just drive it in SD and log data and hope the tuning progressively make the idle/drivability better ?

The log was about 10:1 on the wideband at idle startup - I think it's the 1.15x to the VE tables in the HPTuners help instructions that's pushing it so rich, I will try the same steps without that change today.

I am attaching a brief scan of it idling in SD mode.

Any help or tips would be greatly appreciated... This happen to anyone else ?

Thanks !
Rob (Bad30th)
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Old 11-25-2005, 09:18 AM
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Try reducing the VE table 1200, 800, and 400rpm columns by 10%, 15%, and 20% respectively - go down to 70 Kpa, and see if that doesn't get you closer so it will run enough to get you some good data.
Old 11-25-2005, 10:15 AM
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did you upgrade to the 2 bar or 3 bar pkg?
Old 11-25-2005, 10:27 AM
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You want to work out your idle before you log the rest of the data. Using the steps in the doc your using, let the car idle until you get 50 or so counts at idle. Then take that data and apply it to your VE table. Will be a night and day difference after you apply the data.
Old 11-25-2005, 01:06 PM
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cant he just use 2.0 and create a RAF histogram to get his idle down? Thats what I did, then I did my ve.
Old 11-25-2005, 01:07 PM
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Originally Posted by foff667
did you upgrade to the 2 bar or 3 bar pkg?
I have the 2-bar package, haven't gotten to use it yet though, my current tune still has the MAF enabled and it has some surging/stumbling at cruise... I'm now taking a stab at VE and MAF tuning the under 4k rpm range for drivability. (I have had the 'top end' dyno tuned already but want to work on the lower RPM tuning/drivability - made 504rwhp/512rwtq at 5200RPMs / 16 degrees timing, 9psi, trans is slipping and would not hold past 5k which will be getting fixed soon).

Originally Posted by BLK02WS6
Try reducing the VE table 1200, 800, and 400rpm columns by 10%, 15%, and 20% respectively - go down to 70 Kpa, and see if that doesn't get you closer so it will run enough to get you some good data.
The HPTuners wideband O2 tuning Help file says to multiply the entire primary and secondary VE tables by 1.15 to make sure there's plenty of fuel. I will go back and reduce the idle range VE tables and hope it helps.

The new 71cc heads are really flowing a lot of air it looks like.

Originally Posted by TAQuickness
You want to work out your idle before you log the rest of the data. Using the steps in the doc your using, let the car idle until you get 50 or so counts at idle. Then take that data and apply it to your VE table. Will be a night and day difference after you apply the data.
The HPTuners help file ? The car idles fine with the MAF enabled, so I didn't do anything with the idle. I also have a problem with having P0121, I have the MAP window check disabled on that because of it throwing the code constantly.

I'm beginning to see a correlation between the rough idle in SD mode and the P0121 code. More air than VE thinks should be there ? I do have a 1/4" hole in the TB blade... I will log IAC counts to see where they are.

Thanks for the help guys, keep it comin' !!

Cheers,
Rob (Bad30th)h
Old 11-25-2005, 01:09 PM
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Originally Posted by ninobrn99
cant he just use 2.0 and create a RAF histogram to get his idle down? Thats what I did, then I did my ve.
Hmmm, tell more more... I have (of course) HPT 2.0 with 2bar and EIO packages.

Rob (Bad30th)
Old 11-25-2005, 01:18 PM
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whats your email address??
Old 11-25-2005, 01:25 PM
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PM'd you Nino, thanks.

Rob (Bad30th)


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