Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve

There isn't one set of settings for using this on all engines - here is the manufacturer's advice for this block.

First, you generally want to have no other air leaks into the engine, other than the IAC valve. This means setting your throttle plates to close fully and backing any idle screws off. I mention this because this is a common mistake that many make. On larger engines it is sometimes necessary to crack the plates just a bit to get good idle control, but it is best to start with the plates closed.

That being said, wiring on the chrysler style IAC's can vary depending on which one you get. The best advice I can give you is to start by using a multimeter. Measure the resistances between each pin to locate the coils. in most of the Chrysler style IAC Valves the coils are on the two center pins, and on the two outer pins. So measuring across pins 2-3 (sometimes called b-c) you should get about 50 ohms,and between 1-4 (sometimes A-D) you should have about 50 ohms.

Now that you have located the coils, you need to identify the wiring coming out of your MS. In general there are 2 colors of wire that make up the IAC system (not sure about your numbering). I have about 4 valves on my work bench and they were all a bit different. But, in general, wires of the same color go on one of the coils. The Mega manual really has the best explanation on this (http://www.megamanual.com/ms2/IAC.htm ), I know people always hate to be pointed there but it really does illustrate the figuring out of the wiring well. the info is about 2/3 the way down the page.

As far as the steps go, this will depend on the valve you have. If it is a Chrysler variant, they tend to have more steps than the GM ones do. So the value for initial retraction is usually around 250-290 steps.

Some other things I have noted are that the number of steps when the valve is in the housing can vary from part to part, even from the same manufacture. the step size also varies. Your biggest help will be the stim in this case. When I look to set up a valve I have a MSII V2.2 that I use that has wires soldered on the back (the DB37) that go to spade connectors. To match that I put spade connectors on a connector. This is usually fine for testing on a bench, but the JimStim actually has break out terminals for this sort of thing that might be a bit neater. The Stimv2.2 also has little jumper pads that you can use for this as well.

I know you were hoping for an easy answer but I have unfortunately found little consistency in these valves. The OEM computers do have adaptive idle control that takes care of most of these variables and can compensate rapidly. (DIYAutoTune note - the current MS2/Extra and MS3 firmware does, too.)