My car until 10 days ago used to run perfectly, but suddenly a strange thing happened,
while my engine is on boost now the AFR is 13:1 and it used to be 11,7do you have any idea what to check?
my fuel pump and filter are new
i have changed my fuel pressure regulator
battery bolts are between 13,7 and 13,9V
I have a relay in my trunk and I see only a 0,1V drop from battery and after relay I see a 0,5V drop, on my fuel pump is 12,7 V

what is your advice?

 

12.7v on pump sounds low,btw boost is same before and now?
​​

 

The boost is a bit higher than normal
I do not know what to look for

 

..Try to do boost leak test first,maybe there are some leaks so the turbo works harder

 

I have tried the 0,9 bar setting and I see boost up to 1bar
tomorrow I am going to change line from battery again and make a test

 

I have just change the line from battery to fuel pump
update the alternator
install new fuse
and I have more than 14V in my fuel pump.

Result

Rich mixture at idle 13:1 (from 14,7-16:1)
lean under boost (up to 15:1 with 0,9 bar boost)


now I have bought a new Fuel Pressure Regulator (turbosmart)

i will try to install it and set the correct fuel pressure

 

Finally I found the issue!
the problem was the alternator!
at idle I had 14,5 volts and with car stopped it had almost the same voltage at high rpm
one day I saw WideBand very rich so I had to turn the screw on the ECU to fix it
i didn’t know why
i took a voltmeter, measure my battery’s voltage and I saw 11 volts with my engine at idle
the problem with my alternator was mechanical and not electrical
the strange thing was that my battery light on dash didn’t work at all
i bought another one and now the problem is fixxed
now I have an other problem but this is for a different post

 

Good to hear that you find the issue..