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Old 03-01-2011, 05:36 AM   #1
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Default Temperature Corrections don't seem to be working

Hi guys,

Iíll describe the symptoms and hopefully some bright spark will enlighten me on where Iím going wrong:

Firstly- specs. S/C Miata, with intercooler. IAT bung is just before the intake mani, and I do not believe the sensor itself is subject to heat soak.

I USED to find that my car would run much leaner in cold/winter weather and Iíd always have to re-tune my ve table.

Iíve since totally changed coolant corrected air density from the DIYPNP basemap.

Iíve changed it to IAT corrected:

(deg c)

13 103
16 105
19 107
22 112
25 115
30 120
40 125

This ends at 3k rpm on the assumption that thereís sufficient airflow to not be affected by heatsoak of the intake tubing.

Map seems much better now. Iíve been tuning in the mornings when ambient is about 8 deg c.

WOT is tuned for 11.8AFR.

I went for a long drive over the weekend and WOT was now 12.5WOT. most disconcerting. Ambient was much higher about 15 deg.

This was on the motorway at about 4k rpm.

So it seems the ECU is over correcting for the warmer, less dense air and removing too much fuel.

Where can I play with parameters? It canít be IAT corrected air density, because that ends @ 3k rpm.


Stumped.
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Old 03-01-2011, 06:25 AM   #2
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Quote:
Originally Posted by Paulusuk View Post
It canít be IAT corrected air density, because that ends @ 3k rpm.
Assuming this is an MS2 becaused you mentioned the DIYPNP. In which case the IAT related corrections do NOT end at 3K rpm.
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Old 03-01-2011, 06:46 AM   #3
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Thanks for the reply.

Yes, it is a MS1.

In coolant corrected air density, you can change it to IAT corrected air density. That has parameters for the rpm range it ends at. which is 3k rpm in the basemap.

However, if it really doesn't end there, then i know i've probably been too onservative in my correction
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Old 03-01-2011, 09:30 AM   #4
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MS1 is a different story and if you've set it up to end at 3000rpm, then it should. Watch the gair correction in a datalog to verify.
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Old 03-01-2011, 02:09 PM   #5
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ok- i'll check it out.

if it is, then i'm thinking i need to extend it to redline.
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Old 03-02-2011, 06:16 AM   #6
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Appreciate your support here.

Iíve taken a log this morning.

MAT was 2.8 deg c this morning and Gair was 109

After Motorway journey and heatsoaking traffic, MAT rose to 15deg c. Gair 107.

Both times rpm is around 1500. Is this right?

As expected the taper works, and when I hit highway rpm over 3k rpm Gair drops off to 105.


Can someone comment on whether this is correct?
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Old 03-02-2011, 07:02 AM   #7
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Yeah that's correct.
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Old 03-02-2011, 07:37 AM   #8
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Cheers again.

Any idea why i'm 11.8AFR in cold weather and 12.5 in warm WOT?


is Gair removing too much?
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Old 03-02-2011, 08:00 AM   #9
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Rather obviously I would say.
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Old 03-02-2011, 08:12 AM   #10
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Cheers.

I'll increase the IAT corrections all the way to redline.

Wanted to get this sorted before I start playing with the timing map!
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