Problem with AFR

[RobH]

Hi guys, been doing a bit of work on the Z32 this weekend, have adjusted the fuel maps as high load was very rich (10.5:1). I've made substantial changes to the fuel map (and copied to the knock map as my det sensor is bypassed) but it has made no difference to the high load AFR (!?), still around 10.5:1. Have I missed something??

I have another problem which I'm trying to isolate which is that I can't make more than 1.04 bar (Apexi AVC-r maxed out at 90% duty cycle), I'm wondering if a leak on the high pressure side of the intake circuit could result in both rich mixture at high boost (metered air escaping) and also a reduction in max pressure.

The car is making a lot less power than I would expect, probably around stock levels.

Cheers

RobH

[modulation]

Depending on what gear you are doing your measurements in, you might also want to mess with the acceleration enrichment table.

[Eric]

>> I'm wondering if a leak on the high pressure side of the intake circuit could result in both rich mixture at high boost (metered air escaping) and also a reduction in max pressure.


Yes, it certainly can...but overfueling alone can also reduce max power/pressure

Best is to do a check for (boost/vacuum) leaks to be sure.

-Eric

[RobH]

Hmm...good points. I have thoroughly inspected the intake system and can't find any low pressure leaks, my concern is that the leak I have is only showing up when pressure gets close to 1 bar - this is difficult to identify.

Cheers

H

[klys]

pressurize your intake by using a rubber insert in your turbo inlet(while blocking the other one assuming you have 2.)

with a compressor (and pressure gage) and stop when you've reached ~1bar...

listen if there's anything coming out,

you can also use soapy water and see if bubbles are forming along your intake system.

[nanook]

I'm having the same issue, cannot get boost over 10psi was 14 and afr's richen up to soon and to much, they were fine before the low boost issue.
I suspect boost leak somewere...

[RobH]

Bit late on updating this but I found a couple of leaks in the intercooler pipework. Have sealed them up now and it has made a big difference. Only prob is that I set the system up with accommodation for the leaks and now have to reset it all to get the AFR correct, I'm getting det under heavy load at the moment!

Cheers

H