Idle dip
 

Disclaimer- Please keep it civil, yes i did search and please don't interrupt/thread drift, don't try to solve the world with one phrase.. this solely for those with tuning experience that have actively engaged in trying to solve this idle dip condition. If you're going to clutter or cause distress, leave. Sorry if i may seen like an a#$, i'm not but I'm tired of people hijacking threads with useless junk. We're here to learn and discuss what we each think could help the community.

Has anyone(tuner)logged to see why and what happens when the cars rpm stumble causing a near stall situation before bouncing back up. In my situation my car's idle doesn't fluctuate when the AC is off. They settle at 600 or so when fully stopped, or coming to a stop. When the AC is on, at times, coming to a stop the RPMs will drop just under 600 and the car wants to stall for a sec before correcting itself. I thought before it was always like this and by raising the idle speed like most tuners do, this will be fixed. I see now the car could idle that low without issues unless the AC is on. I was wondering if anyone has logged this event and seen anything unusually causing this. I recall a similar situation in my S2000 after installing an AEM standalone, this was fixed by a tuner "Lance" and i recall him mentioning something about adjusting timing when the AC was on at idle.

I don't have access to a logger my self at the moment, just want to bring this up since i will be digging into the matter as soon as i get my ecutek prokit. If someone does have this condition and the ability to log it, please post it. Thanks :burnrubber:

mine does the exact same thing when the AC is on, while running on E85

It's gotta be something in the software. I already went to the dealer for the service bulletin and they were able to replicate it. They said the updated the software but the car runs exactly the same.

You can try tweaking the idle stability tables (3D table RPM delta vs. Idle target error).

Idle dip
 

Aggh lol that's talking Chinese to me, I really haven't had the chance to log anything or even use the ecutek software but I'll be sure to keep this in mind once I do. As of now im just trying to apply a bit of logic and reasoning to pin some ideas for when I could tweak the settings my self. It seems that the idle speed is low and once it reaches the 600rpm idle and the AC compressor kicks in, for a second the rpms drop too low and cause the near-stall scene before the car compensates. Could be harder that I could imagine to sort out but seems at the moment with the right knowledge about ecutek or any other software, this could be fixed. Thanks for your input guys.

What modifications have you done?

I'm guessing your car is stock ?

You are running stock ROM flashed by dealer.

Your in Miami USA so your probably running a C series ROM

so is it 700C , A00C , A01C, B00C or B01C might be worth asking the dealer what version they flashed if you don't know. They had a couple of goes at fixing idle problems latest ROM revision is apparently B01C

Yeah my car is stock. I had such a bad experience with the dealer that I doubt asking them would help me. Which ever they flashed my car with, it didn't work. I didn't even bother taking it back. I'm planning on tuning soon so maybe that'll take care of it. I like tuning and such so usually with a problem like this I like to try and figure it out. Thanks for your input.

I believe they're supposed to write the version of the ECU they update you to on the bottom of the hood. Check there?

Yeah first thing I checked for since I read the TSB and it specified to do so. Since it's not there makes me wonder if they did anything at all. Dealers dealers, this was on a car with 500 miles and no modifications and even so they don't want to perform their duties. I wish I worked at a service dept for a week to have a clue why they give such a hard time to perform work the factory pays them for.

Sorry to bring this one back from the dead, but any resolution? My idle dips have gotten worse recently, to the point where the car is stalling trying to start in 1st

As per my previous relpy in this thread.

What Calibration ROM are you running in the ECU, their was a series of "fixs" for this from toyota/subaru

ZA1J700C was original then ZA1J900C then A00C , A01C B00C and B01C now we have ZA1JD00C or D for autos. If your not on the latest calibration ID get dealer to update their are TSB out to get updated to at least ZA1JB01C or D.

unless your turbo or substantial mods just take it to dealer and complain is under warantee, it may have other issues like cam actuator, vacuum leak maf sensor issues o2 sensor issues or problems.

If you want to do it yourself buy a Tacrix for $170 and read the Tacrix/Ecuflash thread link below, or take it to dealer and get them to do it.

I have the same issue. While in park with the air on it will idle at 650 RPM, then slowly drop to below 500 RPM. It eventually "stumbles", which seems to get somethings attention and it then quickly goes to 950 RPM. It then settles back down to 650 for a minute and the cycle starts over again.

It does not seem to be coordinated with the air conditioning compressor cycling on and off in any way.

It is a 2015 FRS automatic with 1250 miles on it.

Modifications include dealer installed TRD springs, sway bars and brake pads plus an owner installed master cylinder brace. I am assuming none of those have any affect on engines ability to idle :D

I picked the car up on August 18th, 2014. I am assuming ... possibly incorrectly ... that I have the latest and greatest updates in the ECU. Regretfully I do not know how to determine the ECU ROM version, but if someone has a link I'd be glad to follow it.

Is the TSB number or identifier available that I can reference when I talk to my dealer?

Thanks,
Arvid

excellent advice - thank you. I don't have any mods aside from a K&N drop-in, so I'm fairly peeved about this. I am guessing I'm on the latest calibration, as they've re-flashed it twice already trying to fix it. Cheers!