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runs like ass in SD when cold

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Old 10-24-2005, 07:44 PM
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Default runs like *** in SD when cold

I'm trying SD for the first time and in the process of learning fuel trims. Is it normal for the car to run like total crap when it's cold. Once it's warm and goes into closed loop it runs great but up until then it hesitates and backfires like crazy...is this normal?
Old 10-24-2005, 07:52 PM
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yes. more than likely your open loop table is to rich. A WB would really make your SD tuning a lot easier.
Old 10-24-2005, 08:16 PM
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Add 10% from your open loop air fuel table making it richer from 176*F and below. This will help part of the problem. A wideband will help the rest.
Old 10-27-2005, 08:11 PM
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So I need to add fuel or take some out?
Old 10-28-2005, 06:30 AM
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Originally Posted by Red99TA
So I need to add fuel or take some out?
Well I must of been about half asleep when I wrote that. You need to make the car leaner. Sorry for the confusion. I would remove 10% to start with.
Old 10-28-2005, 07:26 AM
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Hey Black - Beer's not just for breakfast anymore
Old 10-28-2005, 07:55 AM
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It is when you work midnights.
Old 10-28-2005, 07:57 AM
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And just for the record, if you add 10% to that table it will in turn take fuel out.

13.0 + 10% = 14.3



I was half right.
Old 10-28-2005, 08:07 AM
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The open loop fueling table is like a PE multiplier. The higher the number, the richer you'll be. I've leaned my table out a bunch. My startups are not near as stinky as they used to be.
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Old 10-28-2005, 08:11 AM
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Yup, I was thinking of both the multiplier and how we can see the actual AFR in EFILive. If it is displayed as a multiplier ie 1.00 subtract to go leaner
If it is displayed as an actual AFR, ie 13.0 add to go leaner.

Hope that takes the confusion out of it.
Old 10-28-2005, 10:49 AM
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When y'all say the "open loop fuel table", you are referring to the secondary VE table?
Old 10-28-2005, 10:54 AM
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Nope...the "Open Loop F/A" table. Not the same as the VE table(s).
Old 10-28-2005, 12:38 PM
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table b3605
Old 10-28-2005, 03:08 PM
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If I understand it right HPTuners divides the commanded AFR by whatever number is in the table so I need to make the numbers smaller so that the AFR goes up (leaning it out). Is this right?
Old 10-29-2005, 06:27 AM
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Yes. It is just like the PE table.
Old 10-29-2005, 06:28 AM
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Oh, and FWIW, the richest mine ever goes is like 13.0:1 (I think) on startup...that's plenty rich.




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