EFI Tuning and Aircon Request Trims
Written by wolfems on September 9, 2009 – 11:37 pm
Now, we all know it’s nice to drive your car when the weather is nice.
But it’s a little less fun when the engine doesn’t idle smoothly when the aircon (A/C) is turned on.
The load added to the engine when the A/C is turned on can be several Horse Power. That extra power needs to be generated by the engine in order for the engine to maintain the same idle speed as when the A/C is not turned on.
On some small capacity engines with big cams, this can be difficult, as the engine torque delivered can be inconsistent. On larger capacity engines it is usually not as difficult.
To help overcome this, you may need to use your Aircon Request Trim for fuel and ignition to increase or decrease the fuel being delivered, or increase the ignition timing to help improve engine torque under those conditions.
That will help, and along with an idle speed control system like a stepper motor, or pulse wide modulated (PWM) idle control solenoid, you should be able to increase the idle quality when the A/C is turned on.
Until next time,
PS: Getting the idle right on your vehicle can really finish off your project. If you would like to talk about improving the idle quality of your engine, even if has been a long time since the ECU was installed, you can contact us wolfemail@wolfems.com.au.
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