DIY_EFI Digest V4 #590

[Ade + Lamb Chop]

At 15:00 19/10/99 -0400, DIY_EFI Digest wrote:
>
>Date: Tue, 19 Oct 1999 07:53:07 PDT
>From: "Gary Moulton" <gmoabrim at hotmail.com>
>Subject: Manual control of IAC motor
>
>Can someone tell me which terminals of the IAC motor runs the pintle in and 
>out? The wiring diagrams show two coils and the connector has 4 terminals. 
>Does one coil send the position back to the ecm and the other is a 12 volt 
>reversable dc motor?
>
>Application is 1994 Mopar 4.0L EFI in a 1982 Jeep CJ-7, and what I want to 
>do is be able to manually adjust the idle lower than the 750-800 rpm when 
>off-roading. I have connectors and a harness and some electrical experience. 
>I plan to have a switch to disconnect the IAC from the system for manual 
>control and a spring loaded switch to "bump" the IAC position in or out. 
>There is a company offering such a controller for more money than I think it 
>should cost to build one myself. Thanks in advance

I don't know about your system but the mini one IAC is a stepper motor. You
need a driver to run it. The motors I have seen have a permanant magnet on
the spindle then the driver powers coils to step the field round. I am
supprised it doesn't have any feed back of where it is though. I suppose
the ECU gets it to the right place by trial and error. Then resets it's
self back to a postion where startup is good.

There are loads of driver chips around cannot think of on off hand. There
are 2 different sorts of motor too 4 and 6 wire ones... cannot remember
what yours is called tho.

HTH,

Ade