Indication of a problem?

[jdentremont]

Hey Guys,


Long time lurker and I need some help determining what is going on.


I've had my 2013 Scion FR-S for about 5.5 years now and it has 67000km on it. I daily drive it, do some spirited driving and also road trip with it but it has never seen the track or an autocross. My only mods at K&N Drop in and a Greddy Evo3 catback. I've noticed over the past 6 months or so that when going uphill and giving it some gas around 2500-3000 RPM something feel off...I'm not sure how to describe it other than it felt like the tires were breaking loose although I knew that was not the case, I was thinking maybe clutch slip felt like that but my clutch still seems to be doing ok. Fast forward to 6 months later...



I purchased OFT a few weeks ago and decided to try some OTS tunes. So I got everything updated in Open Flash Manger, flashed the correct OTS v4.03 tune and drove it lightly for 60+km and everything was great... Until I started getting on the throttle and immediately seen IAM drop almost exclusively in this 2500-3100RPM range. I spoke with a few people about this and they gave me a list of things to try. I tried a v2 91oct tune as well as multiple tanks of gas one of which I added a bottle of royal purple max boost however I was still seeing negative FLKC and IAM dropping to 0.1 and below. I went back to stock tune and again, I can observe the IAM starting at 0.7 on stock and it hit 0.0 on a 3 hour highway trip this past weekend.


I took the car into Toyota and tried to explain the hesitation i felt in that RPM range, especially while going uphill. They ran some diagnostics, could not find any issues and said compression tests were balanced. I also had a slight rattle in the exhaust which does drone a lot so I got it all welded up a reputable shop and it sounds much better but still no change with how things are running.



The car runs quite well otherwise, If I keep above 3500 RPM I can usually see some positive FLKC and IAM jumps up a bit but on average it stays between 0.1 and 0.3 on stock tune, v2 OTS and v4 OTS OFT tunes, and all knock seems to be detected in that 2500-3100 range. My car definetly seems bogged down a bit when IAM is very low... Is there a major problem with this engine? I would hate to sell the car but if this is indication of a bigger problem, I might want to trade it in before something explodes.


Here is some logs I have on hand, if you want me to log anything else I can do so.


These are on Stage 1 v4.03 OTS:
Right after a flashing the tune, very lightl driving and IAM stays at 0.7 - https://datazap.me/u/jdfrs/log-1531441525?log=0&data=1
And then after 60+ KM I started pushing it a bit and you can see sever IAM drop and negative FLKC usually under high load in ~3000RPM - https://datazap.me/u/jdfrs/log-1531441525?log=1&data=1



Then I flashed back to stock and logged these:
https://datazap.me/u/jdfrs/log-1531441812?log=0&data=1
https://datazap.me/u/jdfrs/log-1531441934?log=0&data=1


Help!!

[humfrz]

Welcome to posting, long time lurker …

Too bad your car is not running good...

All that tune adjustment stuff is way over my pay grade, but I'm sure the tune smart folks will be along soon with some help ..


humfrz

[sato]

Originally Posted by humfrz

Welcome to posting, long time lurker …

Too bad your car is not running good...

All that tune adjustment stuff is way over my pay grade, but I'm sure the tune smart folks will be along soon with some help ..


humfrz

Yeah, I can't help either but subscribed as this is an interesting problem. Hope somebody pitches in. #threadbump

Sent from my Pixel 2 using Tapatalk

[jdentremont]

Thanks for the welcome
I've learned so much in this community and there's lots of smart people, hoping someone can shed some light on whats going on.


I wish it was just a problem with tune adjustments etc but unfortunately she seems to detect a hell of a lot of knock even on stock tune which is where my worry comes from.

[humfrz]

Originally Posted by jdentremont

Thanks for the welcome
I've learned so much in this community and there's lots of smart people, hoping someone can shed some light on whats going on.

I wish it was just a problem with tune adjustments etc but unfortunately she seems to detect a hell of a lot of knock even on stock tune which is where my worry comes from.

"Knock" …?? hmmm... you didn't mention that before.

Do you feel/hear a "knock" or more of a "ping" … ??

Also, where you are seeing a lag in power is when your engine is in the depths of it's dreaded torque dip …. but, a healthy engine will pull through that rather quickly.


humfrz

[Tcoat]

Paging @steve99

[guybo]

Originally Posted by jdentremont

I also had a slight rattle in the exhaust which does drone a lot so I got it all welded up a reputable shop and it sounds much better but still no change with how things are running.

Someone on FB posted about a similar issue. The exhaust rattle was being registered by the knock sensors as a knock and lowered his IAM in a certain RPM range. The shop may have fixed the rattle you heard but it's possible you have others that are causing the issue

[jdentremont]

Originally Posted by humfrz

"Knock" …?? hmmm... you didn't mention that before.

Do you feel/hear a "knock" or more of a "ping" … ??

Also, where you are seeing a lag in power is when your engine is in the depths of it's dreaded torque dip …. but, a healthy engine will pull through that rather quickly.


humfrz

The reason I mention knock is because negative FLKC is essentially knock detection to my understanding. But, I can't say that I hear any knock or pinging, I've tried listening for it but my exhaust is fairly loud too. I'm wondering if what I "feel" going uphill, with the slippage feeling is actually knock, or maybe just just the engine backing off after knock detection.

[jdentremont]

Originally Posted by guybo

Someone on FB posted about a similar issue. The exhaust rattle was being registered by the knock sensors as a knock and lowered his IAM in a certain RPM range. The shop may have fixed the rattle you heard but it's possible you have others that are causing the issue

I've been posting on FB OFT support group to see if I could get help and one guy did mention having "false knock" from his N1 exhaust in a turbo setup and seeing really low IAM like this as well.


If it is just false knock I will be so happy but I really want to rule out any issues first. Even then I'm losing power due to the pulled back timing.

[steve99]

Hi



Are you same guy from facebook


If so i looked at your logs and it looks like its your poir quality 91 fuel thats the issue its causing a lot of knock in the lower rpm high load range.




To get fslse knock indications you usually need the header or overpipe to be hitting on chassis quite a lot or possibly other section of exhaust hitting chassis. Or maybe some other metalic component rattling on engine block, causiing noise that fools knock sensor.


We would need to modify your tune in that area, fueling and timing to reduce this knock. As its quite bad it causes car to hesitate and iam to drop as ecu pulks 3 or more degrees timing


The car stock or tuned with oft requires good fuel to operate well will always be better on 93, some 91 is ok but some brands are poor quality

[jdentremont]

Originally Posted by steve99

Hi



Are you same guy from facebook


If so i looked at your logs and it looks like its your poir quality 91 fuel thats the issue its causing a lot of knock in the lower rpm high load range.




To get fslse knock indications you usually need the header or overpipe to be hitting on chassis quite a lot or possibly other section of exhaust hitting chassis. Or maybe some other metalic component rattling on engine block, causiing noise that fools knock sensor.


We would need to modify your tune in that area, fueling and timing to reduce this knock. As its quite bad it causes car to hesitate and iam to drop as ecu pulks 3 or more degrees timing


The car stock or tuned with oft requires good fuel to operate well will always be better on 93, some 91 is ok but some brands are poor quality

Hey Steve,


Yeah same guy from facebook, I appreciate your input. It's unfortunate to hear that octane seems to be an issue even on stock tune. For what it's worth when I had the bottle of Royal Purple max boost I should have been around 93-94 octane and was still seeing the same issues with negative FLKC in the 2500-3200 RPM range under high load/throttle but otherwise OK. Here is a log with the bottle of RP: https://datazap.me/u/jdfrs/log-15297...=0&data=1-4-14


There's no shortage of high end car's in the area, (Audi R8s, Porsche GT3s, Ferrari 458, Lambo gallardo, tons of GT-Rs, etc) and my understanding is that all running on the same Shell V-Power 91. It should be no worse then Cali 91 so it's unfortunate to be seeing IAM drop to a flat 0 on a stock tunes FR-S.


I've been researching a lot of about exhaust rattle and false knock and I think there's a possibility something else could be loose closer to the headers. For now I've tune back to stg 1 v4.03 OFT OTS tune as it feels way better and "knocks" in exactly the same way as stock tune, so its seems there's no real downside.


The mystery continues...

[Jasonfernandez]

Hello I’m curious if this issue ever got identified or solved for Im have the exact same thing happen and I’m not sure how to fix it.