Ok so on my way home from work today I did acouple 3rd gear pulls while traffic was clear andI noticed something odd. My afr starts at 10.7 but works its way up to 13.5 by 5000rpm. That's lean amI right? boost was down to 15 by that rpm so im not sure why it would be lean.

related mods:
stage 1
agp wastegate
mbc set to spike 20 falling to 15
bfmic
perrin fuel rail
stage 1 injectors

fuel pressure gauge reads 50psi and always has since i can remember. The most resent modI installed was the bfmic this fall. One of my theories was with the 30* air and the intercooler maybe the air is to cold for the pcm to give it enough fuel... I dunno prolly not the case but...
The stock fuel pumps got 30,000 miles on it, is that alot?

guess I need to go for a ride again with someone else to help me watch the gauges. and see if the fuel pressure dropsoff?Just wanted to put this out there and maybe get some opinions. thanks

 

2nd the ridealong. see where everything is at under hard driving. if your fuel pressure is remaining steady, then thats probably not your issue. its at 13.5 at 15psi and about 10 at your spike of 20psi? what are your ratios normally at?

 

well theres a 5 psi fuel pressure loss pretty much at the point of wot.and stays there till redline.

In the summerthe afrwould run 10.2 and clime to 11.7, I never paid that much attention to fuel pressurethen but my setup hasn't changed except for the intercooler.

isn't stock fuel pressure 58? im thinking the larger fuel rail is my problem. The pump cant supply enough volume at the required pressure, if that makes sence.
I think durring the summer it wasn't that bad because the hotter intake air didn't require as much fuel.

 

well, i guess possible. maybe someone who has more tech-know-how. but if your pulling more than the pump can handle... well it makes sense.

 

any ideas on a fix? I'm thinking about putting my stock fuel rail on and seeing if that changes my afr's. Only thing is then I woun't be able to see what the fuel pressure does anymore. But hey if my afr's become good then the problem must be related to the rail.