How to make it 'rev up' upon cold start 7747

[Blake]

So I've been working with the 16144288 ECM in my new Jeep J20 project with a 4.3L v6. I've noticed that upon cold start, the engine revs way up, then slowly backs down to the target idle. Sort of like giving it gas during startup. This really seems to makes for a very 'healthy' cold start and I like that.

So how do I make the ASDU bin file in my other jeep do the same thing? I messed with the IAC target idle in TP but that doesn't seem to do it.

[EagleMark]

Use the Park/Neutral wire. Ground while in P/N and open when in drive.

[Blake]

I don't have the P/N wire connected on any of my TBI conversions.

I'll try it though...

[EagleMark]

Not sure why the 16144288 ECM does it? Maybe it was a manul bin to start with?

That is how the 1227747 ASDU Auto bin works.

[Blake]

Yeah, I dunno. I haven't modded the 288 ECM for a ZIF socket yet, so I haven't messed with it at all (or even looked up the bin).

Here is what Bill over at the binderplantet FI FAQ's says;

B10-orn/blk- Park/Neutral sw. This is optional but I have hooked it into the park sw on the tranny. It tells the ECM when you are in Pk or N. It can be used to give a slight adjustment to idle speed when switching from park to drive and back.

[EagleMark]

That's what a lot of people think the wire is for. Not true, it changes the entire IAC routine in the ECM, in P/N the ECM has limited ability, like high and low, you get somewhere in there. In Drive you get complete IAC control of engine along with many other Idle Paremeters that involve fueling, IAC, O2, etc!

Many people have bought aftermarket wiring harness and last I checked Painless instructions are still wrong/backwards and no one can get a decent idle. Other aftermarket harness companies have a blank spot next to B10... and no instructions.

To understand more on how it really works read the paper written on IAC logic 13 years ago.
http://www.gearhead-efi.com/Fuel-Inj...pdated-12-4-00

There are other ways to get the flare up when cold and TunerPro bin definition has the paremeters to do so, TunerCat does not. It works in manual stock bins but near as good as auto bins. But it would not include the IAC logic to soften change into gear. P/N switch is easy and a good addition to a conversion.