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throttle response problem,help

9384 Views 10 Replies 8 Participants Last post by  ChrisP
Fellow isf owners,
i have problem with the throttle response . I slam the gas and the car will take1 or 2 sec to accelerate and about at 3500 rpm it starts to kick in, the lag is driving me crazy its gotten to the point of being dangerous .last summer i was driving at about 80 km and the truck on my left was changing lanes and almost put me in the wall i slammed on the gas and nothing i mean nada the car did not accelerate i had no choice but to hit the brakes and smoke the triers, it happened 3or 4 more times. My local dealer told me nothing shows up when the hook it up to the computer,any help would be appreciated, thank you
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Fer
I will recommend you Toms throttle controller and driving all the
time on sport mode
with out it I feel I m driving my F with 2 tons of stones in my trunk
try it...you wont regret it ( Call Clark at VIP auto salon )
te lo aseguro papa !

Sergio ISF :D
you are not having any problems. the second or 2 for the car to start accelerating is normal for the car to downshift an appropriate number of gears to do so. so its not throttle response, its transmission react time. having the car in sport mode will decrease the time it takes to downshift. the car only "feels" like it kicks in at 3500 (its 3600) because that is when it starts to get loud.

i am certain that you have no problems. you either are over exaggerating, or you are not used to how the car shifts in auto. try sport mode.
sergio thanks for the response, however , i just took the toms controller out yesterday and the problem still exists.. maybe i wasnt clear on the situation.. lemme give u a clearer example.. im on manual mode traction control is off .. in sport mode... first gear... i floor it ..when i first got the car, i woudl burn rubber until 3rd gear.. NOWW..... i will lose traction after 80 feet or so ... there has to be a problem..... and for the problem on the highway ... its not that i was getting a lag... its that i wasnt getting ANY response... i Floored it and NOTHINGGGG HAPPENED... worst experience of my life...
F-er - I've been experiencing similar problems and it all started when I got the ECU reflash as part of the unintended acceleration recall. The dealer continues to tell me nothing is wrong, but it's gotten so bad that I'm ready to dump the car.
Thank God I didn't take my F in for the reflash and gas pedal update. Sounds like they castrated your cars! I don't even use a Lexus/Toyota dealership for oil change and regular maintenance because of that. Is there a way we can lock the USB port so people cannot access our ECU without our permission? Now I am curious as to whether this is a general problem Anyone else who had the recall done experiencing same?
I googled the problem after reading about it and found this. Looks like you are not alone and this may be widespread problem. I bet Toyota got scared and put in some kind of system control check everytime the ECU received a full throttle signal. This may explain the lag time. Have you tried to depress the gas pedal only 50-75%? Do you still experience the same problem? I am wondering if ECU only does a sanity check when you floor it so if you don't jab the throttle, you may not get the delay?

http://us.lexusownersclub.com/forums/index.php?showtopic=65409
What years ISF is this problem occuring in?

Sorry for the noob question, but I don't want to buy one that has this issue.
I have never heard of this being a problem before with any ISF. However, I have never been happy with the throttle response of my F in Normal mode. When I put it in Sport mode, everything is great and the throttle response is instantaneous, the way it should be. It is my opinion that normal mode is a more economical mode that was programmed into the ECU to get better gas mileage figures for the EPA. Again, I ALWAYS drive in Sport mode. In the 2011 models Lexus wisely moved the Sport Button to the steering wheel so it's easier to activate.

Lou
Thank God I didn't take my F in for the reflash and gas pedal update. Sounds like they castrated your cars! I don't even use a Lexus/Toyota dealership for oil change and regular maintenance because of that. Is there a way we can lock the USB port so people cannot access our ECU without our permission? Now I am curious as to whether this is a general problem Anyone else who had the recall done experiencing same?
I've had the reflash for a long time now and haven't had a single issue, it hasn't even activated on me once, I still do burnouts and races with no issues whatsoever.
Ted C - you're exactly right. It feels as if they castrated my car (which is a 2008 by the way). This started happening immediately after the recall reflash, so it's just way too much of a coincidence. At times I have almost no power (feels almost like really bad turbo lag) and at other times, the engine is revving or the transmission doesn't kick down like it should. Of course these problems don't happen constantly, so I get the usual "we can't reproduce it and there aren't any computer fault codes" from the dealership. I'm no expert, but I suspect the reason there aren't any fault codes is because the problem is with the programming of the ECU itself.
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