Tara

I have just bought a 2001 GS300 for my wife (and because I love the car)

But I find the accelerator response poor. When cruising, flooring the accelerator causes a wait while the car decides to change down then another delay before any acceleration is felt. This two stage effect is awful!

Once things happen the response is polite rather than strong, it does not seem to have much low down torque.

Previously we has an ES300, 94 model, V6 auto. This car did not have the problem. It's accelerator response was good. I can't believe such poor response is normal for a 2001 car.

I have seen threads about resetting the ECU. Could this help? Does the ECU "learn" about driving styles?

We don't have much local (Australian) knowledge on the topic.

UDel

In 2001 I believe some kind of drive by wire system was installed in the GS430 where a computer reads and computes to accelerate when the gas peddle is pressed which causes a slight delay when flooring it. Before 2001 the GS400 had a more direct linkage resulting in pretty much instant response and it being a tenth a second or two quicker to 60 then the GS430 even though the engine was smaller and it made less torque. Your 96 ES most likely has a direct throttle linkage resulting in a more instant response then the 2001 GS. I am not aware of what the difference is between the 300 inline six as not many comment on it but it is probrably similiar between 2000 and 2001 slight acceleration differences. You also have to figure that the 300 is only making 220hp and it weighs around 3700 lbs which means acceleration is not going to be brisk especially at high rpm. My GS430 has a noticeable hesitation between flooring it and acceleration although when put in power mode it alleviates it somewhat.

You could always turbo charge your 300 as the engine responds well to FI. In Australia was the gs300twin turbo available for purchase like it was in Japan. I know Australia got the Nissan Skyline GTRs, Mazda cosmos, still imported RX-7s and Supras after they were pulled from the U.S,evos, sti, turbo ford 4 doors, holden sports coupes and sedans, I think Mitsu FTOs where the U.S. unfortunately does not get these wonderful cars or have only got a few like the evo, sti, holden-pontiacGTO in the last few years. I am not sure about reprogramming the ECU but you could use the search feature.

BC-GS430

Yes the ECU learns. Try resetting it, by unplugging the batt for 10 mins or so. That will probably alleviate the problem for a little. I generally think the hesitation/lag is due to the tranny as it seems like its in 5th by the time your doing 30 mph. Probably to save gas on the big v8 on the 400/430s. Maybe the downshift is the lag?

ocangelfan

I had an '02 GS300, and it definitely had this problem. Same with the '03 GS430, but as was mentioned, the Power ECT switch alleviated this.

Doesn't your '01 GS300 have a ECT switch for Power/Norm/Snow? I'm thinking mine did, but I only had it for a year so maybe I'm wrong. If it does, try doing the same thing in Power mode.

BTW, this is definitely an issue of the transmission not downshifting quickly enough.

Tara

I don't know about the GS430, ours is a 3L in line six, ie CS300. There is a problem with the acceleration response but thats separate to the ability to accelerate once moving. I can live with the less than impressive acceleration but the poor throttle response is just dangerous in driving in Australian traffic.

No we did get the twin turbo Supra's in Aus. But there are grey imports. However turbo lag on poor response will just exacerbate the problem???

Tara

Thanks BC

I will try the disconnection of the ECU. There are other articles about this on various sites. Most seem to suggest that varous fuses are removed. My GS300 is a 2001 gen II I believe.

Thank You

Tara

Thanks Ocanglefan

Yes I do have the Pwr/Norm/Snow switch. But my understanding of this is that it extends the shift points up the rev range. Is that correct? Does it make shifts faster? And this is a two stage problem, the first delay to decide to shift down greards, the second to actually open the throttle.

BTW do you say accelerator or throttle in the USA?

GWELEX

How's the response if you manual drop it down into a lower gear? Does it still hesitate before launch? If not, then I'd say it's ECU related and perhaps clearing it out will make a difference with some aggrsive driving afterwards.

Tara

Good point Gwelex

I have disconnested the battery so I will try both the effect of a fresh ECU and the manual downshifting.

I can't believe Lexus put a car on the road with such abysmal response as normal behavior.

Regards

DASHOCKER

iTrader: (2)

After you reset the ECU (my method is pulling the 20A fuse), take the car out of the drive way and floor it around the block. The car will have a lot more snap durring regular driving.. The ECU will adjust to full power. Works for me

Tara

Thanks Dashocker and all you replied.

I was not aware of resetting the ECU and yes that helped, great!

I also found that Gwelex was right, if I keep the gearbox closer to the gear I will want for performance the response is better. Seems that changing down two gears really throws the ECU/EFI into confusion. One gear is much better. At least that is my seats of the pants impression. I would love something with better data.

I have some conclusions that I would appreciate comments on.....

1. Why design an ECU with this characteristic? General opinion is that it heps with economy and emissions.

2. Why have a PWR swithch that simply raise the gear change revs? Seems logical that, at the same time, one wants to change ones driving characteristics, namely better launches, throttl response etc

3. Does anyone supply a smarter ECU chip that accomplishes point 2.

4. Does anyone supply a better camshaft profile for bottom end torque at the expense of top end performance?

5 Does the facory supply a modification to assist?

Regards and thanks

Vette Boy

It's to soften the ride and make the car a luxury cruiser, no effect on economy or emissions. Very common in many cars, not just the Lexus GS (V-8 Cadilac for example).

I think it also raises the transmission's line pressure and shortens shorten the shift time. I notice the down shifts and upshifts are quicker when I leave the power setting on. I have a 430, perhaps thats the difference. Lexus may assume anyone that buys the GS300 isn't looking for acceleration performace.

PHML

iTrader: (33)

If not already doing so...stick with Premium Unleaded Gasoline.

Also, I'd highly recommend adding a fuel injection cleaner additiive.

Lastly...and this is a must.....clean the throtte body. MInes was very grimey after 5 years (I also have a 2001 model)....and I see why the flap was "sticking". I just did mines yesterday....and now my lag at a dead stop and hesitation during accelerating through a turn is gone.

Good luck.

Pete

DaveGS4

iTrader: (2)

1. Why design an ECU with this characteristic? General opinion is that it heps with economy and emissions. Most Lexus drivers are more interested in smooth driving characteristics, not performance. The learning ECU figures out how the driver likes to drive over time and tries to make the car fit that need. Problem is those that like performance don't always floor it at every dead stop (well some do ) so over time the learning portion gets confused.

2. Why have a PWR swithch that simply raise the gear change revs? Seems logical that, at the same time, one wants to change ones driving characteristics, namely better launches, throttl response etc Toyota has done this for years. General consesus is that the PWR switch only changes the shift points to higher RPM and not the air/fuel or other items. It does absolutely help when you're doing WOT launches for max performance, it just doesn't do as many things as we'd like

3. Does anyone supply a smarter ECU chip that accomplishes point 2. No, but you can get piggyback ECUs like a SAFC II or one that comes with an intake (SRT) that can help... however they don't help as much on launch as higher RPM increases. If you want launch, please search the forum for info on torque converters. Since you have a GS300 with 3.9x gearing already, the 3.76 gears you may read about will not help you.

4. Does anyone supply a better camshaft profile for bottom end torque at the expense of top end performance? Not in mainstream supply, I believe some of the highly customized turbo guys have had custom cams made. Without adding some sort of forced induction, IMO this type of mod would be costly and increases negligible without forced induction to take advantage of it

5 Does the facory supply a modification to assist? Yes, and its called the GS430. If you're very unhappy with performance you should look at trading your GS300 for one now before your wife gets attached to it. It may have exactly the same 'delay' characteristics you describe for your GS300, but the performance difference will more than make up for it.

DASHOCKER

iTrader: (2)

Do a proffessional fuel injection/emissions cleaning at your local Jiffy lube as well.. It really makes a difference.