xbukeye

I am a new member and was looking thru the forum articles and found a message from J Brady that relates to my problem. I just bought a 98 LS400 from a private party--41,000 miles with service performed at rec intervals by Lexus dealer. Great car!! However it has one annoying problem--it is almost impossible to accelerate smoothly from a stop. Pushing the gas pedal slowly doesn't do anything so I continue pushing and then it takes off with a jerk. Also when cruising along at 70 with foot resting on gas pedal, the car seems to surge without applying any pressure to the pedal. My Lexus dealer says it is characteristic with the electronic throttle controls on this model. Can this be adjusted or corrected? I can learn to live with it but I need to know that it cannot be fixed. Would appreciate any information on this.

Horta

Hello and welcome to the Club.

Well I just bought a 98 LS400 about three month ago with only 24k on it. I am also disappointed with my throttle. Your right its very hard to get a smooth take off at times. Mind become obvious when driving slow in my neighborhood and making small turns. Your coasting through the turn try to hit the gas and then a delay in response until a surge of throttle and the car jerks forward.

I took my car in for its 30k service (yes early) and told the dealer about the problem. I thought it was a transmission problem at the time since I just got the car. They of course found no problem. I have read several times now the it seems to be a Electronic throttle issue that seems to be some what common.

Its annoying but since it the ONLY negative issue with my car I can live with it. But if you or someone find out there's a fix PLEASE POST IT.

Good luck
Jerry

JBrady

Yes, yes, this is without a doubt the worst part of the vvti experience. My 96 was SOOOO smooth on take offs and slow speed throttle transitions.

Unfortunately, the surging is a result of how the car is designed. I cannot for the life of me understand WHY the factory didn't correct this. I am considering ways to actually delete the DBW (drive by wire) of the throttle. Its only use is for traction control/VSC. Something I could do with less of or without entirely.

Now, as a short term semi-solution... for those times that you are in stop and go driving situations where it is continuously a problem... I switch the tranny from "power" into "snow". I don't know if all LS400s have the snow setting on the ECT or not but I do. This setting dramatically slows the tip in throttle response and keeps things very smooth. Unfortunately, it also makes quick reponse impossible and limits torque dramatically. In my book, Lexus needs to add this response for very low/slow throttle movements and immediately go to normal or power throttle after this.

xbukeye

Thanks for the information. It's nice to know that I am not the only one to experience this problem. Did Lexus correct this in later LS400s? Is there a way to disconnect the traction control? I sure don't need it in San Diego! With their emphasis on customer satisfaction, I am very surprised that they haven't found a fix. This is my third Lexus and I have always been more than happy with their service. In several cases, they performed repairs for things that were way out of warranty. I will try using the snow setting and I will also pass this on to their service dept. Thanks again.