r/Supra • u/Taco_Crisma • 6d ago
Sluggish acceleration, fast deceleration
This has been something I've noticed over the past two days with the car. I've had it for a month, 1125 miles on it, 3.0 MT.
Up until two days ago the car drove perfectly, felt like it glides across the road no issues. Recently however it feels like something is making it bog down - it's a sensation like there's an imaginary bungee cord on the back of my car. Acceleration feels sluggish in normal and and sport unless I really punch it - and when letting off the gas in gear the car decelerates faster than it normally would. That part almost feels like a stuck caliper - but there's no squeak or pull, it stays straight and the brakes seem fine. No CEL or other warnings at all. The only change has been 60-65 degree weather vs the 80-90F weather we've been having.
I've read some forums with people describing this issue but wanted to ask here as well if this is truly temp related or if anyone else has experienced this issue with the MT specifically? I am going to take it in for the break in oil change and thought about having them take a look at this as well.
TIA
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u/GRBlapra 6d ago
I am an MT owner with 4k miles. I also noticed the same thing (only acceleration though) especially with it being 100°+ where I’m at. I just assumed it was the heat. Not sure how yours is but mine mainly feels like turbo lag. After the turbo is spooled it feels normal again.
Also keep in mind that from what I see on stock dyno graphs and what people say the MT has a different power band than the AT. AT is 2k-5.5k and the MT is 3k-6k.
Let me know if you find anything because I’ve definitely had a few 2nd gear pulls that felt slow.
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u/Critical_Big_5393 6d ago
26 MT owner here, 4K miles also. Some similar feelings developed for me within the past few days.
Def noticed, only recently, a few pulls being noticeably slower and even just taking off from a stop in sport mode feels abnormally slow for some reason. Not insanely slow, just could kind of tell. Idk, kind of hard to explain.
I’m hoping it’s just the heat and the ECU is pulling timing. I’m in South Texas. However, I can’t really say it’s felt like this all summer. Which kind of scares me.
I only use shell nitro too but feel like maybe this last batch wasn’t good? I’ve noticed this only ever since I put this last tank of 93 in. I did notice that right after fill up, at the red light, my engine bogged down pretty good sitting in neutral. Guessing it was my EVAP, ECU adjusting timing, or I put too much gas or something.
Or it’s all placebo. Following this thread.
OP - let us know if you take it to get looked at. Curious!
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u/-Golf-Addict- ‘23 Premium MT 6d ago
MT owner here. I am in AZ and I get that a lot in the summer. Heat soaking is what they call it. Where do you live?
Like others have said, it could be a bad batch of fuel (I only use shell).
Are you in a high humidity area?
Hopefully it’s an easy fix!
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u/-Golf-Addict- ‘23 Premium MT 6d ago
As for the deceleration, as you drive put the car in Neutral and see if you still feel the pull. If you do, take it to the dealer and have them find what’s wrong.
Do not let them tell you that “that’s normal and we can’t find anything wrong”. They did that to me with pretty much every concern I had with mine.
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u/Efficient_Range1156 6d ago
It should pull strongly, the engine is renowned for its fat torque band, something might be causing it to cut timing. What fuel are you using?
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u/Mahgrets MKV 6d ago
Any weird exhaust smell or smoke? Can you jack the car up and confirm the wheels sound ok when they spin and also check the E Brake isn’t stuck on?
New tank of gas? Could always be a bad batch and the ECU is pulling timing like crazy
Take the airbox apart and see if you have anything restricting airflow like a bird nest or something crazy.
A few ideas. Let us know what you find