Acceleration problems.

[007LeBRZ]

Hello!

I have a 2016 brz modded with tomei uel header, perrin 2.5 catback, and is tuned on delicious tune stage 2.

Car has been driving great specially as a daily driver but recently (past 3 months) I got my clutch done, a month after clutch was done, i've had acceleration issues.. local shops couldn't figure out what was wrong with car.. no CEL or anything but the car is not 100% .... last week I found out I had a broken v-band on my exhaust, replaced it, drove around it seemed better but still seems having acceleration issues. I'm hoping it would be just a minor exhaust leak this time. or maybe spark plugs?

any help would be appreciated!

[Dzmitry]

Originally Posted by 007LeBRZ

Hello!

I have a 2016 brz modded with tomei uel header, perrin 2.5 catback, and is tuned on delicious tune stage 2.

Car has been driving great specially as a daily driver but recently (past 3 months) I got my clutch done, a month after clutch was done, i've had acceleration issues.. local shops couldn't figure out what was wrong with car.. no CEL or anything but the car is not 100% .... last week I found out I had a broken v-band on my exhaust, replaced it, drove around it seemed better but still seems having acceleration issues. I'm hoping it would be just a minor exhaust leak this time. or maybe spark plugs?

any help would be appreciated!

Odd. Would be nice to get some data logs for the people that can understand them on this forum, might be able to notice something that would point to an air or fuel issue. Leak is definitely possible considering you've already started off poorly with the broken v-band. But having no CEL does seem interesting in that case, unless maybe the leak is small enough?

[007LeBRZ]

Originally Posted by Dzmitry

Odd. Would be nice to get some data logs for the people that can understand them on this forum, might be able to notice something that would point to an air or fuel issue. Leak is definitely possible considering you've already started off poorly with the broken v-band. But having no CEL does seem interesting in that case, unless maybe the leak is small enough?

*drove car around today, accelerator seems to respond better but there's still a delay with rpm needle going up from time to time. RPM drop during idle isn't as terrible

I thought it'd be spark plugs since I haven't changed them and I'm almost at 90,000 km

and I'm trying to get in contact with my local tuner about the logs.

[Dzmitry]

Originally Posted by 007LeBRZ

*drove car around today, accelerator seems to respond better but there's still a delay with rpm needle going up from time to time. RPM drop during idle isn't as terrible

I thought it'd be spark plugs since I haven't changed them and I'm almost at 90,000 km

and I'm trying to get in contact with my local tuner about the logs.

Yeah I would start with the local tuner to see if he notices anything unusual in the logs. Bad spark plug(s) would certainly cause misfires and poor driving/acceleration. But that should at the minimum show up on a scan of the car. It may not throw a CEL but it would still count up misfires.

[alphasaur]

Post logs

[Qwimby1]

I'm having a similar problem which I haven't been able to diagnose. (14 FR-S) My OBD reading tells me that I'm only getting 80.1% absolute throttle. AFR when I give it WOT is 11.4. I have an ESC on my car but I don't think that's related. I cleaned the throttle body intake and the butterfly is positioned full open, but the car just doesn't feel as strong as it should. Not sure what to do next

[Dzmitry]

Originally Posted by Qwimby1

I'm having a similar problem which I haven't been able to diagnose. (14 FR-S) My OBD reading tells me that I'm only getting 80.1% absolute throttle. AFR when I give it WOT is 11.4. I have an ESC on my car but I don't think that's related. I cleaned the throttle body intake and the butterfly is positioned full open, but the car just doesn't feel as strong as it should. Not sure what to do next

The absolute throttle reading is completely normal from what I recall. You can do some reading from past posts about this. Here's a quick link from the first google search.

https://www.ft86club.com/forums/showthread.php?t=88069

[Qwimby1]

for those who use an ESC, you'll know there's at is a two- position switch that most set at 60% and 80% throttle. That's what I did using my OBD reader. At that time it would also show 100% throttle when I floored it. The OBD was showing 100% absurd throttle, until I swapped out some new batteries for the ESC. I had run the car for a few hundred miles with the ESC turned off. That caused the batteries to go bad. Once I replaced the batteries and turned the ESC back on, I'm getting 80.1% ATP reading. Talked to the folks who make the OBD reader and they told me it's telling me what the ECU is telling it. I have a butterfly valve that's wide open and I'm wondering if there's something else in the throttle body assembly that's telling the car it's only supposed to get 80%.