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idle control under load

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My power steering is putting a load on my motor and it wants to stall. I saw the idle ign control webinar but not sure in my ecu how to make changes. ECU is VEMS

It's common for the idle speed to drop when the power steering is being used and often the ECU will have an input to tell it when the steering is being turned and the pump is under load so that it can raise the idle speed a little to compensate. This is the true solution to the problem as we really need a little additional air bypass under these conditions. Idle ignition control can help but there is a limit to what you can achieve with it - Normally it's only possible to get around a 200 rpm range of control using a sensible range of ignition timing.

I haven't used the VEMS ECU at all so I can't advise on the functionality of that particular product. If you can't find an idle ignition function then you can cheat by using either a 4D overlay table for the ignition based on tps and rpm (basically to replicate what the idle ignition function does when the throttle is closed), or making changes directly in the main ignition map to achieve this effect. I don't personally like using the main ignition table as it can also affect the driveability of the car if you transition through these zones.

Thanks Andre. Here is my idle ign menu. just wondering if i could adjust anything to help with the load.

Attached Files

Hi Cespo500,

Personally, I don't have any experience with the combination of having power steering pump and not having idle air control, so If Andre says that you really need additional bypass air, you probably need additional bypass air. Having idle air control is generally a nice thing to have as it helps on cold start, hot restart and slow city driving +++.

To get the most out of your idle ignition control you need to MBT tune your idle to find out where your engine is strongest. Then you will know what range of ignition you have to play with. I would suggest 0-10° in the main ignition map, and then in the "Idle ignition Advance" window, max advance: 10-20°, max retard: 0-5°, rate of change: same number as "max advance". Remember that idle ignition control is adding ignition on top of main ignition map, so if you have 5° in the main map and 15° as max in idle control, the ECU will give 20° when rpm drops. "Rate of change" seems to be "proportional gain", you can probably set it higher then my suggestion, but the idle will start hunting if you go too far.

The way I MBT tune the idle: Disable idle ignition control. Set the ignition in main map to 10° were the idle is plus adjacent cells, and adjust the idle air screw to get back to wanted idle rpm. Add 2° in those cells and adjust the idle air screw again. Repeat until rpm stops rising when adding ignition. Note the number you have reached and set the ignition in those cells to 10° (or less if necessary) and adjust idle air screw (for the last time). Activate idle ignition control and set max advance to the number you noted minus the number in the main map.

Hope this is useful.

Thank you, going to try it out.

"The way I MBT tune the idle: Disable idle ignition control. Set the ignition in main map to 10° were the idle is plus adjacent cells, and adjust the idle air screw to get back to wanted idle rpm. Add 2° in those cells and adjust the idle air screw again. Repeat until rpm stops rising when adding ignition. Note the number you have reached and set the ignition in those cells to 10° (or less if necessary) and adjust idle air screw (for the last time). Activate idle ignition control and set max advance to the number you noted minus the number in the main map."

So let me get this straight. Turn the idle ign off, Set Ign table at 10° and adjacent cells, Motor Idles at 1000 rpms so set the screw to there " Would you have to calibrate the tps sensor, after each adjustment with the set screw?" So now i add 2° and the cells will be at 12°, Adjust Idle screw, Now lets say the idle no longer moved at 15° I set this in the max advance minus the number in the main map? so 15-10= 5? that would be the max advance?

Attached Files

Happy Monday bump