Injector deadtimes

I had a tune done in my car couple years ago before I was tuning myself the tune is faily close to new combo and a good starting point ..i had a log goin other day when i was doin some light run in driving and discovered that alternator is shot upon looking at logs i notice that the tune goes lean as battery voltage drops indicating that the dead times are not correct in the tune is there a way or a calculation to correct this tune is spot on at 14 volts ..

You can get closer to the actual dead times by tuning your AFR at idle to meet your target with the alternator charging at 14 volts. Then unplug or disable the alternator and the voltage will drop. You can then adjust the next cell in the deadtime table until your AFR is back on target. By switching on the headlights , windscreen wipers, fans etc you can drop the voltage further and continue adjusting the table. Note that this will NOT give you an accurate dead time table - The actual numbers may still be completely inaccurate but what you are getting is the correct difference between adjoining cells. This will be better than nothing though.

You also need to watch that your fuel pressure isn't dropping away during this process as that will also affect your AFR and you would be compensating for this via the dead time.

Thanks Andre