So my car has been running fine for a couple years with the current tune I have on my aem ems 1052u with id1000. The past week the car when moving and clutch in the car should go to high idle 1400rpm but it bounces between 1200 and 2000 rpm until I get close to a stop where the low idle 950 rpm kicks in. Low idle is fine. I was looking in the aem ems idle learn value and for some reason that value use to be 0 -2 but now its stays at -10%
I'm leaning towards the IAC unless its my tune. I've turned off o2 feedback and the surging persists, my AFR gauge bounces lean and back to 15afr.

Any help is appreciated.

 

I think if you buy a hard top it might fix the problem, your car is probably mad at you ....

I dont believe its your tune unless you have changed something from when it ran well to how its running now.....Im thinking IACV as well since its an issue that is happening when the valve is being used by the ecu, have you had a chance to clean it ? is there a way you can reset the ecu so it can relearn idle ?

did your vac at idle change since it was running properly ?

-Lee

 

Hey Lee.

I don't think my vacuum has changed but ill definitely check for leaks. Gonna clean the IACV this weekend. I also have a spare I can swap in to see if that fixes it. There isn't really any idle relearn for the AEM ems that I know of. I bet it's the hardtop. You should give it back to me at a discount

 

IACV and extra air in the motor are both good starts - frequently when a car develops a vacuum leak of some kind - aka one of the emissions lines leaking or the throttle play getting a bit of gunk and staying cracked the EMS will still be using the same idle air control ratios as it was before it started having problems and it will take a bit for it to trim the IACV values down until it idles properly - if you did nothing to the car to change those values i'd check vacuum leaks and spray out the IACV

 

Ya good place to start take brake clean when it's idling and spray it alllll over the intake side and all hoses if the idle changes u have a leak....

Gl man.... No hardtop for u (hardtop nazi)

 

Ok replaced the iacv with a clean spare I had. Still doing it. Ill check tomorrow for leaks.

 

Found the problem. My PCV valve was stuck open. Threw on a spare i had in my tool box and all was back to normal.