Hey guys,
I have a 408 with a 236/230 .600/.600 115lsa. I am running a 2 bar tune and am having some strange idle issues that *seem* to be heat induced.
I had major surging going on at stopped idle (in gear, A/C on) of like 300-400 rpm. I adjusted my IAC parked table for the IAT in question (the heat had caused my IATs to be closer to the 104*F cell than the one below which is why it showed up as summer hit) and now have very intermittant and *slight* surging when stopped, but even more annoyingly, I noticed the truck no longer idles at the desired rpm, but 100-200rpm higher (idle is set at 850 and hits between 950 and 1040rpms), and moving from gear to neutral or park causes a sruge to 2000rpm. It will do this multiple times. It is also showing a slight surge during moving idle (like deceleration).
I've noticed that vacuum changes follow the surging, which seems to follow spark changes and/or AFR going lean. I'm kind of at a loss on what to try next.
I started out by adjusting the base spark tables to 26* for low kpa and low rpm (0-40kpa, 400-1200 rpms), adjusting the IAC airflow trables by SOTP to eliminate hestitation and stalls, and adjusting the IAP table.
Any suggestions? Also can anyone the IAC parking algorithm so I have a better feel for which tables I should be screwing up ?