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hot starts, lean at idle

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Old 02-10-2014, 10:07 AM
  #21  
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Originally Posted by Braineack
you have MSI?
MS2 Microsquirt N76
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Old 02-10-2014, 11:52 AM
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I have it too, but I'm still NA and my AIT is on front side of stock, rubber elbow, just after the filter box, so it sees all radiation from radiator. Of interest is JasonC SSB's newest comments on injector dead time changing with temperature. Me... I'm hoping that my problem goes away when the AIT is located on FMIC cold tank, but it sounds like ScottP is still having an issue.

Last edited by DNMakinson; 02-12-2014 at 10:02 AM. Reason: Had "Jacob", rather than "JasonC"
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Old 02-10-2014, 12:06 PM
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Have you tuned your MAT corrections?
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Old 02-10-2014, 02:12 PM
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Originally Posted by Braineack
Have you tuned your MAT corrections?
Yup. First I tuned it to stay at 100 and then added to try and cure hot restart but with to much mat (115 GAIR) I run pretty rich and still lean on hot restart.
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Old 02-10-2014, 03:11 PM
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I think I am going to play with my ASE. Thats the only think I can think to change. Maybe crank them up to tune out the hot restart then change my WUE so Im not running pig rich on warm up.
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Old 02-17-2014, 11:56 AM
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Increasing my ASE didnt help much really if it all.
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Old 02-17-2014, 01:25 PM
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It should help, while it's activated. The problem with using it as the sole solution is that the time of the heat soak varies per driving conditions, and will not help stop-and-go heat soak.

Overall, I totally agree with setting the ASE for each cold condition's first 30 or so seconds (to keep from having cold take-off stumble) and letting the WUE take care of the rest of cold conditions. The WUE wizard seems to assume this as well, as it seems to target the curve to the AFR and no extra enrichment.

But, you would have been adding the ASE at high temps, rather than low, and the WUE would already be off.

Is your AIT in front of the radiator?
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Old 02-17-2014, 03:18 PM
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If MAT corrections keeps Gair at 100%, then how are you going lean?

What would be causing you to not have enough fuel?

post a datalog of it.
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Old 02-17-2014, 05:13 PM
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I will data log it. Its not AITs my GAIR is always above 100 and my IAT sensor is right after the intercooler in direct air flow.
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Old 02-17-2014, 10:18 PM
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Nvm. Found it

Last edited by whizbang18T; 02-18-2014 at 07:48 AM.
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Old 02-18-2014, 10:28 AM
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Lean restart log attached. Just ordered a new fuel pump and will change the fuel filter at the same time as my 190 hp comes in from lightning motorsports. Not sure if that will help or not.
Attached Files
File Type: msl
Lean.msl (333.9 KB, 109 views)
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Old 02-18-2014, 07:13 PM
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Is it really 100* in Texas? Your CLT is only 160, but your MAT, at the intercooler is showing 100. When the AFR first starts reading, you are OK, but as the ASE tapers out, then car goes lean. If the AIT sensor is lying (heat soak), then this can make sense, even with the 1.8% correction, depending on the total MAT corr curve.

The other thing I see is that the VE table is going from 42 to 47 as the idle control valve moves to hold the RPM (VE changes with MAP). I wonder if that area could use more tuning, in particular, the lower KPa having the VE raised.

Last would be, in conjunction with above, injector dead time. If smaller than actual, then very small changes in pulse width can cause high error at idle.
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Old 02-19-2014, 09:35 AM
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My iat sensor is right after the cold side. I have adjust my MAT correction table so it reads around 103%

I'll adjust my ve at idle more but idk how the hell I would still be heat soaking. If I up my GAIR I'll just run even more rich.
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Old 02-19-2014, 11:31 AM
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My other worry is say I crank up IAT correction then Ill run rich as ****. So then I run VEAL and tune my idle, then It will go back to still having shitty hot starts. It will just be chasing its tail.
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Old 02-19-2014, 04:15 PM
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I wouldn't change MAT for idle, and I wouldn't allow VEAL to adjust VE in the idle area. If the hot restart is an idle issue only:

1) I would manually increase idle area VE cells.
2) Allow EGO to control AFR at idle
3) Tweak idle VE so that, under normal conditions EGO is pulling about 3% at idle, and at hot restarts EGO is adding about 3% at idle.

Do not change MAT so that the entire VE table is wrong under some conditions. Rather MAT correction should be so that the majority of the VE table is correct over changes in AIT (MAT).
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Old 02-19-2014, 04:42 PM
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I've done that before with no sucess. I guess I will try it again and make it more aggressive. Thanks for all the feedback and answers.
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Old 02-20-2014, 09:50 AM
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So I made it much more aggressive in the EGO settings. I got it to go to 15.7-16.1 on restarts with no idle surge then with the tap of the throttle drops in to the 14s. Once down the road car stays in the high 13s at idle. I do not have seq injection. Now I need to tune WE cause its very rich warming up but that should be easy. Thanks for the feedback David props to you.
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