Lean AFR after 5k

[offroader1006]

My AFR goes from 10.5-11:1 to around 14.5:1 at 5k-up on my PC-16.

i figured it was jusut the file, but any attempts to alter the MAF signal with an SAFC havent been able to richen the mixture.

this leads me to believe i may have a fueling issue.

Turning the FPR up to around 68psi got me where i needed to be at the top end, but of course i had a dip in the middle.

anyone have any experience with this much of a lack of fuel? i was thinking maybe fuel filter or pump, but i wouldnt think the fuel pressure raising would be able to move more volume if it was clogged.

[Side-Step]

What injectors and turbo are you running?
What was the pressure set before you up'ed it to 68 @ WOT?

[GetBoosted84]

What's your injector duty cycle look like?

[offroader1006]

genesis 315's with the k04.

pressure is supposed to be 3 bar. and thats not 68 @ WOT thats 68 at idle with vac line off

and i have no idea what the duty cycle looks like, what block is that?

[GetBoosted84]

It's block 002. Then you have to do this calculation:
Injector Duty Cycle = Injector On Time / (2 Revolutions * (1 second / (RPM / 60 seconds) * 1000 ) * 100

Also, I had to run 386 cc injectors at 4 bar with my GIAC Hammer file setup (on my 01). Maybe your injectors are too small? We'll see after you post your duty cycle I guess.

[offroader1006]

It's block 002. Then you have to do this calculation:
Injector Duty Cycle = Injector On Time / (2 Revolutions * (1 second / (RPM / 60 seconds) * 1000 ) * 100

Also, I had to run 386 cc injectors at 4 bar with my GIAC Hammer file setup (on my 01). Maybe your injectors are too small? We'll see after you post your duty cycle I guess.

i will have to wait until i get my new laptop, keg crushed the old VAG

[offroader1006]

i have a 16.32 ms at every rpm on block 002

that formula comes out to a very small decimal.

[mike-2ptzero]

It's block 002. Then you have to do this calculation:
Injector Duty Cycle = Injector On Time / (2 Revolutions * (1 second / (RPM / 60 seconds) * 1000 ) * 100

Also, I had to run 386 cc injectors at 4 bar with my GIAC Hammer file setup (on my 01). Maybe your injectors are too small? We'll see after you post your duty cycle I guess.

The PC16 file is tuned for 310cc injectors at around 2.7-2.8 bar. With the 3 bar FPR it runs pretty rich down low.

It almost sounds like his fuel pump isn't moving enough fuel, this could be just a warn pump or his fuel filter might be clogged causing fuel pressure to drop at 5k+ rpm which means reduced fuel supply.

[GetBoosted84]

Your Injector Duty Cycle comes out to this:
RPM OT Duty
3000 16.32 40.8
3500 16.32 47.6
4000 16.32 54.4
4500 16.32 61.2
5000 16.32 68
5500 16.32 74.8
6000 16.32 81.6
6500 16.32 88.4

* OT = Inj. On Time

Mike is right, not your injectors... they are only getting to 88% by redline.

[mike-2ptzero]

Yeah I would start looking for something that is causing a fuel supply restriction on the car. This tune has been around for nearly 10 years so plenty of people have been runnnig it and still run it.

[offroader1006]

i am gonna try swapping pumps this afternoon.
the filter is only 1 year old

[Jerstillman]

Yeah i personally would swap filters and go from there. Thats usually the problem with low fuel output at WOT

[offroader1006]

swapped filters last night, the fuel looked like jack daniels coming out of the old filter.

in the first to runs to ~5600 rpm, the 02 voltages stayed in the mid .8's

and i noticed my cold crank time decreased as well. i plan to get in a full run and see what the logs look like.

[jakecro]

zOMG/oes noes, you didn't drink teh jack daniels did you?!

[offroader1006]

no, but your mom did.


buuuuuuuuuuuuurrrrrrrrrn.

sizzle sizzle

so if your AFR looks like this:

<--dyno fail

suspect your fuel filter.


edit: BTW it put down 189 whp at 4200rpm before stopping due to the AFR. this is after more supporting mods to the PC-16 setup.

namely a P&P mani and a VR6 OBDII throttle body

[offroader1006]

Update. Went to the dyno last month. Same crappy afr. The safc did alter the curve, but with the safc maxed rich, it was still waaaay lean. Then I noticed my fuel pressure was not rising with the boost as it should.

Then I started thinking, I have had no residual pressure and long cold starts since I went pc-16. I immediately face palmed and realized I needed to try a different fpr. I just put 034's items at the bottom of the list of possible failures, especially because they are newer. Today I tried an old 4 bar fpr and hooked up a pressure pump and the pressure rose exactly 1:1. And no residual pressure dip after the engine shut off.

Eagerly awaiting a new fpr now.