EFIDynoTuning Forum

This is a screenshot of 1861 from A9L2
The idle air writeup says to divide all the cells by 6. That would be:
Which one should I use?

its already done

So, use the A9L2 version without dividing by 6?

you skipped over a major section of the idle air write up read it all

Sorry boss -- I re-read it twice now, and I'm still not clear. Most of it says it's only provided for informational purposes only?

Howdy JBasham! I am confused on the same instructions from the Idle Air as you are I believe...
Excerpt from Idle Air:
"FN1862 / FN1861 Divide entire table (all cells) by 6, this will result in a value of 0.172 at the top warm ECT cells that the engine normally operates at"

I went with Decipha's same response to you/me and kept the table as the default from the current A9L2_220405.bin. Prior to adjusting the table and after restoring it, my idle has been pretty good over all. Initially tuning the MAF table my idle was horrible but as I dialed it in it got better and has been spot on for a bit. So I proceeded with the doc and now I'm on to the Mechanical Idle as you seem to be.

I gather you stopped around where I did where it said DO NOT proceed after, it's only FYI. Still it also says to do not continue if your fueling/KAMs are not right. I finally got my KAMs in so I can proceed but I'm still confused at least by the FN875 functions. FN1861 I'll go with "it's already done for you" in the current bin as the master Decipha said :)

Excerpts from Idle Air:
"This does not apply to those using the mechanical idle control, in the mechanical idle control FN875N must = 0.6 and FN1862 = 0.172 at a warm stable idle.
Likewise, the idle air Drive function FN875D must contain the actual air mass needed to reach a desired rpm WHEN THE ENGINE IS AT STABILIZED WARM IDLE ONLY and is multiplied by the isc table multiplier FN1862D. Typicall the when at a warm stable idle, the cell(s) in use is 1.000"

Here's a screen shot of the main functions mentioned in the Idle Air doc which are idle. Does yours look the same?
The FN875 ones seem like they should have values in DSDRPM as the doc implies . Per the doc the AM column for FN875N needs to all be changed to 0.602 (realized TunerPro / Strategy altered it to 0.602 after setting it to just 0.6 per dox but I see that's normal behavior to round up/down to nearest... voltage?) despite no value in DSDRPM. The FN875D (Drive) doesn't contain any data, just 0s.

That's where I think you and I are both getting lost/confused. Sound about right?

These are the main tables I found:
FN1861
Z_FN1861_EXT (appears to automatically mirror FN1861)
X_FN1861D (slightly different #s than FN1861 & X_FN1861_EXT)
FN875D
FN875N
ISC Multiplier FN1861

where the table reads .172 at 200 degrees engine temp. ( The first pic in this thread. ) That's a set, looks right to me.

My take as a layman; Ford needed a way to settle the idle if the car had a small vacuum leak to cut down on warranty or complaints. So the Idle air valve can remove idle air if needed due to "pirate air" getting to the engine. Sort of worked ok on bone stock cars.
Decipha has us set the throttle stop and if we get a vac leak we will fix it, but I don't think his setup will decrease below the base idle.
Ford base idle =450rpm
Decipha base idle =750rpm

He got rid of a bunch a crazy crap we don't need.

Thank You Red :) I know he carved a lot out for us to make things easier and he's done an amazing job in every respects :) So for the FN875N and FN785D, still leave those as is in the screen shot now too?

Hmmm. FN875N and Fn875D D is for drive on autos trans so I'm not sure since i'm on a stick shift car. He may not use it. I think on the write up he said make 875N and 875D match and tune D if needed.