1986 ski centurion boat, 351W, gt40P heads, edelbrock performer rpm, 1227747 ecm, 72 lb/hr injectors (@18 PSI fuel pressure), .490/.490 lift, intake 278 duration, exhuast 282 duration, 112 lobe separation
1969 camaro, 355ci, performer RPM intake, camel hump heads, 1227747 ecm, 454 throttle body (@18 PSI fuel pressure),
2016 Chevy Cruz
2014 Chevy Silverado
You are welcome. If I understood better what you are trying to do here, perhaps I could point you in the right direction. I assume you are trying to control the idle speed. what idle speed are you trying to achieve? Remember that with that cam, you may need to idle a little higher. My guess is somewhere between 750 and 850. Anything below 500 automatically will invoke stall saver and move idle to 500 minimum, and I am not sure if the cam you are using will like idling that low. Also, there are a lot of conditions that may or may not adjust the IAC postion (like the park/Neutral switch, or A/C which I assume you don't have)
Last edited by jim_in_dorris; 05-16-2014 at 08:36 PM.
Square body stepsides forever!!!
1986 ski centurion boat, 351W, gt40P heads, edelbrock performer rpm, 1227747 ecm, 72 lb/hr injectors (@18 PSI fuel pressure), .490/.490 lift, intake 278 duration, exhuast 282 duration, 112 lobe separation
1969 camaro, 355ci, performer RPM intake, camel hump heads, 1227747 ecm, 454 throttle body (@18 PSI fuel pressure),
2016 Chevy Cruz
2014 Chevy Silverado
You have no use for P/N... but the ECM does. Hopefully it is in Drive at all times or this is all a waste of time.
Second remember we changed other IAC tables! So don't expect all table to be in sync with bin! Besides the IAC logic of this ECM/OS is known to be dismle at best but can be twaeaked to work! This is how programmers have gone through code with others and came up with this conclusion.
Third Your out of IAC steps so your dot going to get any more idle RPM! 0 is good when it's the hottest day after a full throttle run and checking IAC counts. Being an in depth tuner with your conversion you should know this is usually maybe 8? or 7? But now we hit a hotter day and a WOT run, pulled hard, worked harder then normal and we hit 0.
See the problem is your hitting 0 already! Way to soon. Going to have to give it a little more room to breath so most of the time you have say... 10? Now you have that extra 10 for IAC to play with to adjust Idle!
HTH!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Glad your feeling better!
Right now the Park/neutral wire is open so the ECM thinks its in gear all the time (like a manual transmission setup). I do have a neutral safety switch, so I could use it give the ECM feedback when it is in drive and neutral. I was always under the impression it was not necessary with this application being in a boat (velvet drive transmission). Do you see any benefit in using it?
What changed in the IAC tables? Is there a link that describes the changes?
I'm aware that I should have 7 or 8 steps for idle adjustment. However, someone suggested that this is not necessary in a boat. I was trying to maximize the air flow over the throttle blades to make the smoothest idle with this cam. However, if the right thing to do is adjust for 7 t0 10 steps (fully warmed up), I will do it.
1986 ski centurion boat, 351W, gt40P heads, edelbrock performer rpm, 1227747 ecm, 72 lb/hr injectors (@18 PSI fuel pressure), .490/.490 lift, intake 278 duration, exhuast 282 duration, 112 lobe separation
1969 camaro, 355ci, performer RPM intake, camel hump heads, 1227747 ecm, 454 throttle body (@18 PSI fuel pressure),
2016 Chevy Cruz
2014 Chevy Silverado
Bookmarks