Yup, originally I just turned up the BISS but since then I also used the tactrix/OpenECU to increase the ECU idle settings. Unfortunately that did not resolve the issue yet. I'll try to get a log of the MAF signal to see if that helps to diagnose what's going on.

 

Did you turn the BISS back down after you changed the ECU idle targets?

l8r)

 

No - should I?

 

If you remember how far you changed the BISS, it wouldn't hurt to put it back to where it was from the factory. If you've given the ECU new idle targets via ECUflash, then there should be no need to turn up the BISS.

l8r)

 

Okay, I don't think I have useful maf data yet. The xede "high speed logging" didn't seem to log anything; and the low speed one might not provide the datapoints we need.

Freq0 below is the maf; presumably the voltage scaled to 0-100. The two points where it says RPM "4" is where it dropped too low. What might make this log even less useful is that it seems that most values stay the same for two log entries; that doesn't seem right to me? (BTW AN0 is knock v, AN1 is wideband AFR)



I'll try to find a better tool to log this.

 

If you have the tactrix cable, you'll get much more useful logs via Evoscan.

l8r)

 

Okay, did a log of a stumble with evoscan (after hitting the evoscan revving to 3000 issue) - I'll get a superspeed log when I have another minute too.

 

Here is a evoscan csv log with superspeed enabled, logging to screen disabled.

In entry 243 rpms dropped into the 400s.

 

Okay, this snippet from your logs (digested into Data log Lab) is a good diagnostic view..

First thing I need to know exactly what mods are on the car.. And WHAT settings are you using in your XEDE

1) Airflow at idle should be anywhere from 25-40hz, as you can see its way high, at around 100hz and dropping to 60hz.. If you were not moving at the time I would see this as throwing your idle control and trims way off..

2) Injector pulse is way high when it drops, THis is an indicator to me that your fuel trims were out of range and reset themselves..

3) O2 voltage is pretty steady when it happens, which I do think is odd, butI have no answer for this one.. But it does drop to .7v from .9v just afterwards, and therefore its trying to adjust fuel trims again.

Did you alter your idle settings in XEDE by adding "Fuel" at idle that can increase the MAF reading? This would explain the higher reading I see in the ECU or did you rescale injectors through it?

If your idle frequency is 50 hz for example, use the feature to lock the idle frequency at that normal idle frequency.. See if that stabilizes your idle..

The ECU is looking for 30-45hz at idle if its really high and the fuel trims are a little off, you'll freqently see it reset the trims to zero and see the symptoms your describing.

 

another interesting thing I noticed is your TPS is 15%, If this is a log at idle where your not moving, it should read lower, and you should adjust your TPS value so its .6v which should read 0-1% TPS, check this first before you do anything else..


In your logs it looks like you've already locked your idle airflow at around 44hz, so you have a good start there if thats the case..

The more I look at it, the more I'm inclined to have you look at your TPS sensor first before you do anything else.. If your car really is sitting at idle, 15%tps is not right.. I doubt the BISS fudges your TPS sensor reading.. Make sure the throttle cable isn't keeping it from closing all the way also..

 

Thanks Jack! That gives me a good starting point to see what might be going on. Right now I did add some fuel and timing at idle to see if that helped; I'll probably back out all the changes to see what it does without them.

The above log was with mods Xede + Smart, XedeFlash, Jun 264 cams with cam gears, TB exhaust + tubular o2, walbro 255. (So I am running the stock air intake + filter and for that log the stock dv)

First thing definately will be to look at the TPS.

 

Yeah your really not running a combo that would be prone to stalling for absolutely no reason.. Though the stock (and crushed 1G DSM) DV will be partially open and recirculating at idle in theory you could plug up the dv and recirc line and see if the car idles better, just don't drive it that way.