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Old 05-09-2015, 02:58 AM   #1
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Default Unstable idle... maybe?

Sorry for the noob threads and whatnot - trying to figure it out as much as I can without making new stuff.

Anyways, I can't seem to get a stable idle (at least compared to stock) and not sure if its because the tune I have or if this is just normal. Also should note that my wideband reads normal up until 15.5 ish afr and then MS reads differently than the gauge (AEM UEGO). It's powered from 12v radio and grounded to MSPNP2 pin 5.

Thanks in advance for help. Should also note that in logs, while cruising, real AFR is around 16.2-17 and creeps back and forth between that.

Files were to large for mt.net so its linked via dropbox
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Old 05-09-2015, 11:59 AM   #2
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thats too lean to idle. aim for 14-14.5:1
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Old 05-10-2015, 12:02 PM   #3
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Is idle rpm only affected by VE tables? I was fiddling around with closed loop idle settings and ended up making the car run at 5k rpm on start up.

Also still having problems with TS and WB agreeing with each other. On idle they both agree and at 4k rpm with no load they agree, but when I start going on the highway, things start to get out of sync at cruising speeds. Bad ground or is the calibration off?

Thanks again all
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Old 05-11-2015, 04:00 PM   #4
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Try using the same ground for the wideband that the Ecu is using. That will help eliminate the issue. Sometimes you have to use the custom calibration in MS instead of just selecting the wideband you have to get it to read correctly in MS.

Also like brain said your AF ratios are pretty lean, you should add more fuel. I found that my car like to idle best in the upper 13's/ lower 14's and cruise in mid 14's.

You can add an extra column before your idle cells (i have 600rpm) so that MS can use that to bounce off of. Ms is reading more than one cell at a time so getting the surrounding cells tuned right will help you have a stable idle

Timing is also huge for achieving a stable idle. An extra column here before your actual idle (around 600rpm) will help the iding of the car and also help with idle droop when you get off the throttle
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