$EE EVAP system tuning

[steveo]

hey guys, hope you can help me with this one. i have an annoying problem with an LT1 $EE

i've deleted the CCP system completely, and found an issue that i can't seem to get around trying to tune it out

first off, the coolant temp to enable CCP cannot be used to disable the system, as it shares some kind of boundary with CL modes. i presume this is a 'feature' so the lack of a horrifying unmetered air leak that the CCP sends through the throttle body wont taint the regular BLMs.

although it is possible to enter closed loop before the CCP coolant enable temp is reached, this limits all normal driving activity (non decel/idle) to BLM cell 18, so effectively, raising the temp out of range limits you to cell 18, dropping all 'normal' blm cells.

one cool thing is, dropping the CCP enable temp to below freezing seems to push it into regular block learn mode almost instantly after CL is entered.

i have also noticed (only through datalogging so far) that there are obviously some hidden correction factors against CCP duty cycle. i can only assume there's both airflow and MAP corrrections.

as the purge duty cycle increases, my AFR goes to shit, and i get nasty part throttle BLM splits.

i have attempted to correct for the lack of unmetered air and fuel fumes with maf calibration, somewhere in between 15 and 20% maf scaling up until 90afgs or so to be close

...now here's the kicker; i think someone already found a hack to disable it properly, including any calibration factors. from the manual for LT1EDIT Expert:
The Expert Editor includes this function menu, it is not in the Standard version of the editor. It allows you to toggle thefollowing PCM functions On or Off.

Transient Fuel
This disables the Charcoal Cannister air purge.

[steveo]

i guess the easy way would be if anyone happens to have a copy of LT1EDIT that would be willing to send me two bins to diff; i would be so happy to figure the hack out myself...

[steveo]

starting to think i'm going to have to brush up on my assembly to solve this.. i've only ever done motorola risc assembly, this 68k shit looks a bit different for sure

[EagleMark]

I was hoping someone had an answer for you... but we do have some dissasemblies avalable that may have it or be easier start to find it?

http://www.gearhead-efi.com/Fuel-Inj...ull=1#post2423

[steveo]

i'm definitely working with those, unfortunately nobody has located any evap system stuff in there yet, so it's all on me.

i can't seem to even locate a memory address for the CCP duty cycle, which i assume would be the best place to start, since the CCP actuator routine must reference this location, as well as whatever the hell compensates the AFR for it being open.

still holding out hope an lt1edit user will get ahold of me so i can just diff the thing....

[EagleMark]

You sure all these problems are from CCP? I've done transplants of the LT1 motor and not had issues like this? Now the AIR Pump dose cause some issues if not disabled...