RodC

I've been noticing a little quirk with my tC lately. As far as I can remember, it used to pull smoothly even with the gas pedal pressed to the floor, but lately it feels different. If I am going from a rolling start, say from 10mph and then suddenly to full gas, the car sort of shudders at the highest RPMs as the speed picks up. Same thing happens from a standing start.

Now, I am not a racer, and the car is an automatic, so launching is not exactly rocket science. This situation usually arises when I am entering the freeway, going from a red meter light and suddenly having to get up to 70mph in a short distance in order to merge with traffic. There is a really short onramp which I often use, and the only way to merge in time is to floor it.

Anyway, just wondering if it's normal or if I have to fix something. I don't think it has to do with the transmission, because it happens in the middle of gears. Seems to be engine related. I wonder if it has something to do with the intake.

SquallLHeart

throttle lag due to drive by wire

and small reason for intake for losing small amount of low end torque

RodC

Hmmm, I never thought of the drive-by-wire. So it looks like everyone experiences the same thing. Any kind of workaround solution?

AKAvensis

see how its not a perfect rainbow?

AKAvensis

btw i feel the car is faster if you dont floor it all the way so that it changes gears at 5k, and look there is the proof, you hp goes down 20 if you keep it floored

DanielNC06

ive felt the same thing in my manual tran. and i wondered if something was wrong but i later assumed it was just me over-analysing the car once i adjusted to it. i feel it most when going to from 2k-3.5k. But i also noticed that i feel it most when the engine is cold...i'm not really concerned though, its not obvious enough for the passengers to notice..

BZinn1

I noticed the same thing in my auto but have adjusted to it.....if you floor it 100% down it does seem to get a lag in acceleration......if you leave it just off the floor a little bit it pulls harder......

IntegreS_350

I have a lag in my 08 (automatic)-- =/

deezy

I have a 08 automatic and I experience the same thing pretty much. If I floor the gas the RPMs shoot way up but it feels like the gears don't immediately "catch". From the conversations here on the forum I've gathered that this is normal I guess.

RodC

Okay, I feel much better to know that everyone else has the same thing. I just always assumed that flooring the gas would give the fastest acceleration, especially in an auto, but it sounds like a gentler approach works best. I will try to learn to work around the throttle lag.

RnB180

I usually dont floor it from a slow roll or stop. I use an automatic too. IMO if you do that you'll quickly hit redline and doesnt switch over instantly.. the car also feels like its lacking power.

Usually if you you let off the gas and accelerate right after it switches over right away.

TongMan

Flooring the gas pedal is not the best way to achieve the best horsepower. I've learned not to floor the pedal, but to slowly feel your way as you press the pedal.

tCizzler

I have a question that's kinda related... When i cruise at 2100 RPMs the car seems to be very jerky as well, would someone else try it. You might not think its happening, but if you try it and pay attention you might notice something. I'm hoping i'm not the only one. For instance, cruise in 2nd or 3rd at 2100- 2200 RPM and just stay there, the car seems to gallop a little, like it want to take the FU<K OFF!!! but you're holding it back or something, it's really weird. I'm not saying it feels like something "wrong", but it's different than any other car i've ever driven.

I originally thought it was the VVT-i, but then i realized it doesn't work like VTEC-YO! It is constantly varying, right??

Thanks for any input... And so you can't say i'm jacking this thread , yes my car does the same jerky acceleration, similar to the feeling i just explained.

Rsquared_TC

yeah i would agree that slowly (but still quick) pushing down on the pedal for an auto is better.

lriicelboy

i thought someone would've gotten it by now. correct me if i'm wrong, but on the automatic transmissions, if you floor it, the ECU will downshift automatically, which causes the RPMs to shoot up. that's probably why you feel the shutter. it happens to me too, by downshifting, the RPMs go into a better range to create more power to the wheels or something like that.

Deathwish238

Yeah...the gas pedal in an auto is also going to control what gear you're in to some extent...if you floor it all of a sudden when going 10 then it's gonna shift into 1st or 2nd which takes a little time and then you feel the jerk from the change in acceleration

RodC

No, that's not it at all. I have driven other autos without experiencing this. I believe this was already attributed to throttle lag.

Killface

Mine isn't jerky at all. The shuddering might be related to bad gas, or you could need a fuel filter. I have had previous cars shudder due to fuel delivery issues, usually the fuel filter.

RodC

Bad gas as in going to the wrong station? Which brand is considered good gas? I know it's not a fuel filter as I started noticing it under 10,000 miles.

Deathwish238

Shell, Exxon/Mobile, Valero, Chevron are all decent. I only get gas from Shell. Just don't get cheapo gas like Racetrack, Quicktrip, Walmart, etc