RPM Dip - ECU? - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

humfrz · 09-24-2019, 10:05 PM

Quote:

Originally Posted by HKz

there was nothing to fix like the crickets. if variations in idle speed bothers you guys so much, then I think y'all aren't doing enough actual driving!

OR,..... maybe they need a bigger engine -

Didn't used to have those problems, back in the day.

humfrz

DarkPira7e · 09-24-2019, 10:19 PM

I raised my idle to 900rpm. No more stumbling, also doesn't dip low if you clutch in from a high rpm and let it drop, it stops right at 900. Even with a/c or defrost at full speed

As much as I love a calm 650rpm idle, this car acts say better at 850-900 for me.

humfrz · 09-24-2019, 10:32 PM

Hell, our old 2 cylinder John Deere tractor would idle quite smoothly at 150 RPMs.

However, it had a 10,000 pound flywheel -

"You can take the boy off the farm, but you cannot …." something or other -

humfrz

JesseG · 09-25-2019, 12:30 AM

Quote:

Originally Posted by HKz

there was nothing to fix like the crickets. if variations in idle speed bothers you guys so much, then I think y'all aren't doing enough actual driving!

I agree, unfortunately driving in traffic on hot summer Texas days happens sometimes.

And something interesting about the crickets, my FR-S had them when I first bought the car. They’ve been gone after I started filling up with 93 octane at Valero. *shrug*

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Nevermore · 09-25-2019, 04:31 PM

Mine got pretty shaky once during a 90 degree day when I was stuck at a light for almost 15 minutes in city traffic. I don't recall what the RPMs were doing, but the temp gauge read normal so I couldn't figure out why it was shuttering. I turned the AC off and opened the windows. Car was happy, I suffered.

Sasquachulator · 09-25-2019, 06:21 PM

I remember my old Corolla XRS doing an RPM dip when stopped when the AC was on. There was also a clear drop in power too when the AC was on.

More recently however, my Scion IM is doing it.

At times I stop at a light and I can feel the car (and see the RPM) fluctuate between around 500ish to 1000rpm when stopped (leveling off at 750ish for a period before it does it again).

I figured it had something to do with the A/C compressor due to previous experience but I don't have defog or anything that I would think would activate the AC compressor...….so I thought it was weird.

I did have an oil change and that SEEMED to have fixed it for like a week or two but then it came back.

Ill live with it, but I don't know why the car fluctuates the idle as much as it does.

sodjer · 09-26-2019, 02:44 PM

Quote:

Originally Posted by Pwoods

Just an update on my situation. I changed my OFT tune to stage 2 and it seems to have fixed this issue. I’ve heard that a stage 1 tune on a stock car will smooth out the idle, but I don’t know for sure.

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My car would do the RPM dip to the point of almost dying as well, after flashing to OFT Stage 1 it cleaned it up and hasn't done it since. Now I just gotta get my header on so I can flash stage 2...

CoolHandMoss · 09-26-2019, 03:31 PM

I have ECUTEK and I was able to get Mike to add in some padding when the throttle closed with the A/C on. Now it kind of hesitates before dropping to idle. It works quite nicely.

venturaII · 09-26-2019, 04:27 PM

Worst ecu, EVER.

Ultramaroon · 09-26-2019, 04:50 PM

Quote:

Originally Posted by venturaII

Worst ecu, EVER.

Got me. Spit my food a little.

Seriously, I know a bunch of local owners, driven many, worked on many...

Not once have I seen one that dipped or shuddered like described here. There's a little bit of it coming from unanticipated changes to accessory load but nothing dramatic.

Pwoods · 09-26-2019, 05:53 PM

Quote:

Originally Posted by HKz

there was nothing to fix like the crickets. if variations in idle speed bothers you guys so much, then I think y'all aren't doing enough actual driving!

Just for the record, I don’t drive my car I just rub it with a diaper

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HKz · 09-26-2019, 07:04 PM

Quote:

Originally Posted by Pwoods

Just for the record, I don’t drive my car I just rub it with a diaper

Sent from my iPhone using Tapatalk

nice! the tradeoff is you'll most likely avoid a spun bearing, never have to deal with the torque dip and you won't have to change out those pesky poorly designed brakes!

09-25-2019, 04:31 PM	#19
Nevermore Wayward Member Join Date: May 2012 Drives: Hot Lava 86 Location: Bust of Pallas Posts: 3,336 Thanks: 1,669 Thanked 2,312 Times in 1,386 Posts Mentioned: 50 Post(s) Tagged: 3 Thread(s)	Mine got pretty shaky once during a 90 degree day when I was stuck at a light for almost 15 minutes in city traffic. I don't recall what the RPMs were doing, but the temp gauge read normal so I couldn't figure out why it was shuttering. I turned the AC off and opened the windows. Car was happy, I suffered. __________________

09-26-2019, 04:27 PM	#23
venturaII Only users lose drugs. Join Date: Nov 2014 Drives: All the time Location: Shrewsbury upon Worcestershire Posts: 1,834 Thanks: 888 Thanked 1,078 Times in 681 Posts Mentioned: 3 Post(s) Tagged: 2 Thread(s)	Worst ecu, EVER. __________________ "To know a thing well, know it's limits. Only when pushed beyond its tolerances will true nature be seen." Amtal Rule

09-24-2019, 10:19 PM	#16
DarkPira7e Rust bucket enthusiast Join Date: Feb 2017 Drives: 2013 Turbo Firestorm FRS Location: Vermont Posts: 4,054 Thanks: 3,313 Thanked 4,204 Times in 2,112 Posts Mentioned: 33 Post(s) Tagged: 0 Thread(s)	I raised my idle to 900rpm. No more stumbling, also doesn't dip low if you clutch in from a high rpm and let it drop, it stops right at 900. Even with a/c or defrost at full speed As much as I love a calm 650rpm idle, this car acts say better at 850-900 for me.

09-24-2019, 10:32 PM	#17
humfrz Senior Member Join Date: May 2013 Drives: 2013 FR-S, white, MT Location: Puyallup, WA Posts: 30,432 Thanks: 29,826 Thanked 32,845 Times in 16,844 Posts Mentioned: 715 Post(s) Tagged: 2 Thread(s)	Hell, our old 2 cylinder John Deere tractor would idle quite smoothly at 150 RPMs. However, it had a 10,000 pound flywheel - "You can take the boy off the farm, but you cannot …." something or other - humfrz

09-25-2019, 06:21 PM	#20
Sasquachulator Pavement Grey Join Date: Dec 2011 Drives: 2020 Toyota Camry XSE, 2017 BMW X1 Location: Calgary Posts: 3,116 Thanks: 109 Thanked 2,256 Times in 1,221 Posts Mentioned: 8 Post(s) Tagged: 0 Thread(s)	I remember my old Corolla XRS doing an RPM dip when stopped when the AC was on. There was also a clear drop in power too when the AC was on. More recently however, my Scion IM is doing it. At times I stop at a light and I can feel the car (and see the RPM) fluctuate between around 500ish to 1000rpm when stopped (leveling off at 750ish for a period before it does it again). I figured it had something to do with the A/C compressor due to previous experience but I don't have defog or anything that I would think would activate the AC compressor...….so I thought it was weird. I did have an oil change and that SEEMED to have fixed it for like a week or two but then it came back. Ill live with it, but I don't know why the car fluctuates the idle as much as it does.

09-26-2019, 03:31 PM	#22
CoolHandMoss Senior Member Join Date: Jan 2018 Drives: 2013 FRS Location: VA Posts: 305 Thanks: 1 Thanked 87 Times in 55 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I have ECUTEK and I was able to get Mike to add in some padding when the throttle closed with the A/C on. Now it kind of hesitates before dropping to idle. It works quite nicely.

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