AEM EMS S13 SR20DET idle issues?

[rebornS14]

anyone ever have this problem? i have a S13 SR with a AEM EMS standalone and every now and then, very randomly my idle will climb to 2200ish and stay there. it goes it away but there's nothing i can do to MAKE it go away. just goes away on its own after a little bit of driving. Regular idle is set to 900 and most times its fine and stays there.

Mods:
AEM EMS for S13 SR blacktop
AEM 3bar MAP sensor
AEM UEGO Wideband O2 Sensor
HKS 264 CAMS
Blitz Air-Intake
Stock T25 turbo
Greddy turbo downpipe
Apex 3" catback
3" testpipe

[xpertsnowcarver]

You should check the AEM forums. I find all my answers there.

How long have you had your AEM EMS installed, and how long has this problem been happening? Did you tune it yourself?

[rebornS14]

for about a year now, happened when i first got it installed and while tuning then went away without changing anything on the tune. its weird. ill check AEM forums.

[xpertsnowcarver]

Maybe this will help. Took this out of the AEM EMS User Guide V2.0 PDF file.

Idle Tuning Procedure

The first step before tuning the IAC system is to determine the direction of the motor.
The language of the IAC motor is in percentage. This is not percent open or percent
of airflow, it is rather the full-scale percentage of the motor where 100% may be fully
closed or fully open. Do not assume that a larger idle percent gives a higher idle
speed. Some factory units actually decrease Engine RPM as idle percentage
increases. It is very easy to determine which way your specific IAC system works.
· Open AEMPro and connect to the EMS.
· Confirm that the throttle position is set properly (closed < 1%, WOT > 95%).
· Confirm the AFR or that the vehicle has sufficient fuel for idling and that the
vehicle is at the normal operating temperature.
· Open the Idle Template and set Idle FB Below rpm to a conservative
3,000RPM and set Idle FB Above rpm to 400RPM. Set both Idle On If TP
Less and Idle Off If TP Over to a conservative 5%.
These settings will activate the idle circuit whenever the engine RPM is below 3,000
RPM and the throttle is below 5%. These settings are not necessarily drivable but
they will allow the vehicle to idle on its own so you can begin tuning.
· Start the engine.
· Get the vehicle to idle. This may require creative throttle movements to
stabilize the idle until it catches itself.
· Confirm that an increase in the Idle% vs Target Table will increase RPM
rises.
· If RPM decreases, select the Idle Invert option in the Advanced Idle
Template.
· Shut off the engine.
Now that you know how the IAC motor responds, you can start setting up the idle
tables and idle options.
· In the Advanced Idle Template, set the option Idle FB Minimum to -50%
and Idle FB Maximum to 50%.
· Set the options Idle FB Dead Band+ and Idle FB Dead Band- to 0.
· Open the Idle Template and set the entire Idle Target Base table to
3,000RPM.
· Start the engine.
· After a few seconds, confirm that the Idle Target parameter is 3,000RPM (if
not zero-out all.
· Add or subtract idle percent from the Idle% vs Target Table until the Idle
Learned Value parameter is 0% (you may notice that the idle motor will not
rev the engine this high but that is common).
· Drop the Idle Target Base table to 2900RPM.
· Add or subtract idle percent from the Idle% vs Target Table until the Idle
Learned Value parameter is 0%.
· Drop the Idle Target Base table to 2800RPM.
· Repeat this process for every 100RPMs until 500RPM is reached.
· Set the Idle Target Base table to your desire.
It is a good idea to set the Idle FB Minimum option to a small feedback percentage
to keep the engine from stalling (5% is typical). The Idle FB Maximum can be set
high to band aid tuning flaws (15% is typical). The Idle FB Dead Band- option is
typically set at -25RPM while the Idle FB Dead Band+ is typically set at +50RPM to
keep the idle steady. A typical Idle FB Below rpm is 1700 which keeps the idle
motor from trying to idle at slow vehicle speeds. Set both Idle On If TP Less and
Idle Off If TP Over options 1% higher than the Throttle parameter when the engine
is running and the throttle is at rest.

[rebornS14]

wow, thank you for that. i will forward that to my tuner and see if he has any feedback on that.

please if anyone else knows or has had this problem give me some input. thanks.