Idle control no isc

[John Tosh]

Is it possible to still control idle without the use of a stepper motor? Or is it a case of using the idle screw on the throttle body?

[CamB]

I asked a related question over here:

http://www.linkecu.com/forums/G4Forum/190229329

The way I understand it, you will still need to get a stable warm idle using the idle screw and sensible ECU settings, then the idle ignition target can help to stabilise / target idle In differing conditions (warmer/colder, falling rom, etc). I am hoping it's as easy in practice as in theory, but in my case the engine idled fine back when it had no EFI, so see this as an upgrade...

[sardengineering]

This is correct, you may achieve acceptable idle control in applications where no dedicated valves or solenoids are in place by using a combination of idle related tables within the PCLink software and the Link ECU does a very good job of this. It helps if you can open up the throttle a little beyond the norm position it would be in, but not too much, your aim would be to achieve a decent air flow based on engine vacuum and parasitic loads which are active at idle. What you should keep in mind when attempting something like this is that adding ignition advance has a direct correlation to engine torque and torque is what will make allowances for increasing engine speed. What an idle control valve or solenoid would do is add more air to the engine allowing the potential for more torque, this additional torque can help to cut back on high variances of ignition advance between operational idle conditions and actual driving operational conditions of the engine. Ignition advance values should always transition smoothly and here in lay the compromise of idle control without a valve or solenoid.

Hope this helps answer your question and provide some insight. Should you need more specific assistance based on practical scenarios please feel free to follow up accordingly.

Cheers!