E38 speed density hot start stays lean

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10-15-2019
Tferrellsn95

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E38 speed density hot start stays lean

I am working on a 08 G8 GT single turbo in speed density. Fuel is E85. If I start the car cold or after sitting for an extended period, It starts and idles great but if I cycle the ignition and attempt a restart, it goes very lean shortly after starting and stays lean until it dies. I am attaching 2 logs. In the one from 10.14, you can see STFT max out but pulse width does not increase. I have verified fuel pressure and its steady at 58-60psi. I am stuck on this thing and in a time crisis now. Thanks Guys!

Attachment 93786
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10-16-2019
Tferrellsn95

Bump
10-16-2019
07GTS

your VE table needs to be smoothed think of it as airflow as it is and airflow dosnt do that between cells, some possable causes for afr swimgs are charge temp multiplier, tps multiplier, also u havnt set the dtc for failed maf all 3 fail on first error, high fail 2 low 1, set counts to zero, also stoich table has changes best to keep stock
10-16-2019
Tferrellsn95

I will make the changes you suggested. Thank you for your response 07GTS!!
10-18-2019
granatl

I'd swear you're hitting the same thing that always gets me. If I then shut-off the car and reflash the SAME parameters, it'll be normal the next try.
10-18-2019
Tferrellsn95

Quote:

Originally Posted by granatl

I'd swear you're hitting the same thing that always gets me. If I then shut-off the car and reflash the SAME parameters, it'll be normal the next try.

I made the suggested maf fail changes, smoothed my ve a little and tweaked my iat & ect multipliers and the issue is gone. I hope that helps your situation as well