problems tuning low setting

[G9S1X]

i hopped up from 390cc(auto) to 550cc injectors, for low settings i started with -15 across the board. i know this is rich as hell because u can watch raw fuel being dumped from my exhuast and it bucks at 18psi (not like fuel cut, like when you vent your bov bucking). now that we all know its rich, why does my o2 trim read 120% - 140% at -15 across? and the low fuel trim never moves, sits at 107% no matter what i set the low setting to. i also have a 255walbro low pressure pump on stock fpr. thanks

 

[turbolarry]

i also have a 255walbro low pressure pump on stock fpr. thanks

With this hint you sound like you alredy know you need an AFPR.

 

[G9S1X]

i knew you needed an afpr if u got the high pressure walbro but everyone said you shouldnt need one for a low pressur one

 

[i'm boosted]

I have a walbro 255 low pressure and you definitely need one.

 

[SUPERMAC]

this may sound dumb, but have you checked your plugs yet? they need to be regapped. 18 psi will easily blow out your spark plugs. when they blow out it feels like your car just all the sudden died. hard jerking and sputtering for a second. then it runs fine once the boost goes back down. very not fun feeling.

chris

 

[HighPSI TSi Guy]

lean it out another like 7% or so, and change your spark plugs... you don't need a AFPR unless you're stock one is broken