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 IAC/Idle control (currently 297 views) |
| fxdlidon |
| Posted on: Friday, January 9th, 2009, 8:26:54pm |
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Due to the recent cold weather I've been having to play around with the idle - when the enggine was 1/2 warmed up it would die every time I pulled up at a set of lights!
As part of this I set the 'minimum value' (top left on the idle tab) to 0 ( the setting it came with is 20 ) - it didn't affect the idling but the boost seems to be coming in much quicker and stronger 
I've had a look in the manual and the 'minimum value' is the lowest %duty cycle that the ecu will let the IAC drop too - I'm guessing that a certain amount of the manifold pressure was being perminantly bled off via the IAC. |
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| Chris S |
| Posted on: Saturday, January 10th, 2009, 11:03:39am |
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Interesting, I would have assumed that even the minimum value would only be applied once the ECU entered the idle control state (i.e. TPS == closed && rpm < max_idle_rpm).
I guess it would be easy enough to verify with a scope.
My adaptronic is not plugged in ATM as I didn't have time to get my cold start issues ironed out, but I also found that the base idle settings didn't agree with my car. I had considered looking at finding a higher frequency solenoid valve (e.g. 100Hz) where the PWM can be used to control valve lift rather than the binary open/closed of the standard cappo valve (if only to get rid of the ticking at idle). I think modern EGR valves work like this.
I also had an issue with my WBO2 sensor. I think that there is a significant lag in the rs232 WB output. When using that and in slow-convergence mode, the ECU kept on increasing the fuel map at various places. I need to try using the 0-5V WB analogue output of my controller to see if it suffers the same lag. It's very noticeable when you plant your foot back down after the fuel cut on over-run (using standard ECU), the A/F gauge still reads very lean for 1/2 second or so even though the engine is clearly being properly fueled. This might just be an issue with my tech-edge 2J1 though.
I really need to summon the willpower to get back to this having used up my reserves cleaning & rust protecting the rear wheel arches  |
Last modified Saturday, January 10th, 2009, 11:07:35am by Chris S |
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| Chris S |
| Posted on: Saturday, January 10th, 2009, 11:13:49am |
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Oh, and my plan for sorting out the idle when I get back on the case was to disable the closed loop control,
then set all the open loop efforts so that idle at various temps etc was on the high side (e.g. 1200-1500 RPM). The closed loop could then be used to pull the idle down to the target speed rather then have to add effort to bring the idle speed up. |
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| fxdlidon |
| Posted on: Saturday, January 10th, 2009, 12:18:55pm |
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You can see the idle value in the gauges window. I thought it would drop to 0 once you touched the throttle but it doesn't - even with the minimum value set at 0 it still seems to vary between 4 and 9 until you get up to about 4000 rpm.
That's bad news about the tech-edge 2J1 - I got one for christmas, if the weather hadn't been so cold I'd have fitted it by now.
That's exactly how I got my idle to work properly, the main problem I had was the lack of a signal for electrical load (AZ-1 wiring is slightly different) but now the closed loop works perfectly even when I turn the lights on. I did need to keep the target rpm at 1100 till the water temp gets up to 60 deg though. |
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| Chris S |
| Posted on: Saturday, January 10th, 2009, 2:23:57pm |
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When you wire up the 2J1, if you connect up the NBsim signal so that you can easily swap the original ECU back in, make sure you leave the 2J1 signal ground disconnected.
I used the original +12V O2 sensor heater supply to power the 2J1, then you just connect the NBsim to the signal pin on the original O2 sensor connector. The signal GND in the 2J1 is connected to chassis GND whereas the sensor GND to the original O2 sensor does not seem to be, and I got very erratic water & air temp sensor readings when I had it connected.
Hope that makes some sense, I'll try to take some pics & post the details of how I wired it up.
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| Ricou |
| Posted on: Sunday, December 20th, 2009, 2:33:36pm |
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Don, I'd be interested to see how you set your idle.
I had some troubles to get a stable idle which wouldn't stall when I turn the lights on. In fact, I noticed that the lights weren't signaled as an electric load - I might check the wiring if I got the motivation 
About cold starting issues: I still have some troubles starting when engine is cold, but I found a nice trick to help: in Corrections, Transient Throttle, Asynch Accel Pump, set the value for 0 RPM to something like 40 or 60.
Like this, it enables you to inject some gaz by pressing the throttle before starting the engine. It seems to help pretty well in some cases for me |
Last modified Sunday, December 20th, 2009, 2:33:55pm by Ricou |
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Cappuccino Owners Club › Specific Discussion Boards › Adaptronic ECU › IAC/Idle control (Moderators: )
