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-   -   Idle Issues (https://www.miataturbo.net/aem-59/idle-issues-72187/)

Leafy Apr 15, 2013 08:48 AM

Idle Issues
 
So car runs pretty decent now. Idle hunts when the iac is plugged in. I dont understand it. It idles like a rock with the iac unplugged and the timing locked @ 10 degrees. I basically completely turned off any idle controls by zeroing out the tables and setting p to zero in the idle control logic, plug the iac back in and unlock the timing and it huts. IT SHOULDN'T DO THAT, if all idle controls are completely zeroed out. And for some reason, even with idle P at zero it still generates an idle learning value, which it also shouldn't do.

I do also think I may have a wiring issue, all of my sensors seem to have an odd 0.08ish volt noise to them, so I had to do things like soften the accel engagement to keep that from turning on. I'm using the factory NB sensor ground, however my knock sensor is also grounded there with a stacked ring terminal, yes I know thats bad and thats going to be the number 1 thing I check once I'm back to the car next weekend.

Leafy Apr 15, 2013 01:55 PM

Well I've found two issues so far. The P value in AEM works backwards, zero is the max p value for control. AND apparently the iac speed should be around 2500um not 20.5, that could be causing some issues, maybe even my electrical noise.

x5kid May 21, 2013 12:23 AM

Hey Leafy, quick newb question :/
How did you wire up your iac was it through a gpio? and how did you come about on the setup Finally got my car up and running only to find out my car was idling at 3k rpm because my iac was not wired in and setup. Any help would be much appreciated once again. My tuner is asking me to finish this last little hickup before taking it in, I need to know the frequency in hz in order to get the idle motor tuned in. But must configure it in the software as the iac pin and then adjust the pulse width if im not mistaking?

Leafy May 21, 2013 12:50 AM

I got mine for trackspeed with their special boomslang made harness. Though I've had to manually track through pretty much every wire in order to have it do things that I wanted it to (like VICS and clutch switch), but I cant remember if its on a GPIO, the massive 700 page PDF for the ems4 should have that info somewhere in the very beginning.

I'll get my laptop out tomorrow night and check the setting I came up with for iac frequency (technically its iac period, fucking stupid AEM). I only have an NB iac number, and I know for a fact the NA is different.

FAB May 24, 2013 01:04 AM


Originally Posted by x5kid (Post 1013807)
Hey Leafy, quick newb question :/
How did you wire up your iac was it through a gpio? and how did you come about on the setup Finally got my car up and running only to find out my car was idling at 3k rpm because my iac was not wired in and setup. Any help would be much appreciated once again. My tuner is asking me to finish this last little hickup before taking it in, I need to know the frequency in hz in order to get the idle motor tuned in. But must configure it in the software as the iac pin and then adjust the pulse width if im not mistaking?

Yes it's using a GPIO - It will actually require you to use a PWM GPIO, so pin 5-8 of the GPIOs will work.

x5kid May 26, 2013 12:42 PM


Originally Posted by FAB9Tuning (Post 1014797)
Yes it's using a GPIO - It will actually require you to use a PWM GPIO, so pin 5-8 of the GPIOs will work.

I'm trying to get it setup and dialed into the software, but I'm not having any luck. I wired the IACV to pin 5 started enableing that pin (is it suppose to be pin always on, or ground on? And how would it be turned on) I'm not to familiar with the gpio pinouts/setups.

FAB May 27, 2013 01:36 AM


Originally Posted by x5kid (Post 1015460)
I'm trying to get it setup and dialed into the software, but I'm not having any luck. I wired the IACV to pin 5 started enableing that pin (is it suppose to be pin always on, or ground on? And how would it be turned on) I'm not to familiar with the gpio pinouts/setups.

It sounds like you're trying to set it up under the "configure outputs" menu. You actually need to find the "idle" tab and make sure that in the "idle PW output" is set to pin 5.

EB Turbo Jun 5, 2013 11:45 AM


Originally Posted by Leafy (Post 1001119)
even with idle P at zero it still generates an idle learning value, which it also shouldn't do.

P only determines how the idle learns. it has nothing to do with turning idle control on or off.


I do also think I may have a wiring issue, all of my sensors seem to have an odd 0.08ish volt noise to them, so I had to do things like soften the accel engagement to keep that from turning on. I'm using the factory NB sensor ground, however my knock sensor is also grounded there with a stacked ring terminal, yes I know thats bad and thats going to be the number 1 thing I check once I'm back to the car next weekend.
This may not be causing your idle problems but it definitely causing driveability issues. It sounds like you do not have idle control set up properly. You will need to tune your Idle % v Target table. If that is not tuned you will not have proper idle control. You cannot rely on Idle feedback to do all of the heavy work for you. You will have very inconstant idle control. You may want to post your map or post some PC logs of the idle tab.

EB Turbo

Leafy Jun 5, 2013 11:47 AM

Its been sorted out for a while now. Once I figured out that the p-term was backwards, and it got better when I added the passenger side intake manifold ground strap.

My only idle issue now is that the engine instantly dies when the fans first turn on at idle. And that idle on hot start is lean for the first minute.

EB Turbo Jun 5, 2013 12:03 PM


Originally Posted by Leafy (Post 1018582)
My only idle issue now is that the engine instantly dies when the fans first turn on at idle. And that idle on hot start is lean for the first minute.

Those are easy fixes. You will see the load change when the fan comes on. Modify those cells to fix for the incorrect AFR. There are a few starting tables that have to deal with warmup enrichment, Start extra v temp and, Start extra decay. Depending on where your concern is, you will need to modify one or all of those tables.

EB Turbo


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