Discuss all things tuning in this section. News, products, problems and results.
Hello, maybe a dumb question.
Can IACV be eliminated when using a stand alone ECU?
Technically yes, but you might have some issues getting a stable idle depending on what all is done to the car. Most standalone ECUs can drive an IAC motor.
Is there a reason that you want to eliminate it?
You can generally create a stable idle without one with more bypass/shifted throttle stop and a bit of a hole in the ignition timing around idle but it will rob you of a little off throttle vacuum which some people may notice if they use it to steer the car.
The off throttle vacuum issue is going to depend on the cams. That's not an issue unless you have aggressive cams (or big ports if it's a rotary).
If you delete the IACV you will want to raise the base idle speed by adjusting the throttle body (either an air bypass screw or the throttle stop screw). If you adjust the throttle stop screw to crack open the throttle plates you will need to make sure the TPS is still reading correctly. Also, additional spark will raise the idle. It will be difficult to compensate for accessory load however, such as headlights, A/C, or power steering.
Eliminating the IACV is possible but you will need to accept an idle speed that is going to move around a little. Idle ignition control can do a pretty good job of maintaining a stable idle speed once the engine warm, however you're going to usually find that the engine will idle very low when it is cold and may require you to use the throttle to keep it running for the first few minutes.
thanks for your input. Mainly I was just curious. For now I will be keeping the IACV :)