Running Rich ??

[Jan Larsson]

I turned down my fuel pressure a bit (around 40PSI), recommended is 42 PIS for the chip I'm running with my 42.5 injectors.

Anyway, the TTA is running rich and it's been running a bit rich most of the time. Adjusting the fuel pressure (down) seems to make it run abit richer ... what else would affect this ?

 

[Razor]

Jan,
Your fuel pressure you set using your scantool. Put the scantool on BL and then adjust fuel pressure so the BL numbers are +-10 from 128 under all driving conditions.

Some chips will be rich at idle on purpose, this is done to smooth out the engine.

Post back your BL number at idle.. bet its high(adding fuel). Typically a vacuum leak will cuase this.