czr73

I'd pay attention to this diagram and consider changing your Throttle Controller, as well as adjusting your TPS to .70 with a multimeter. Might help to clean the TB also !!
Also, lubricate the accelerator line with 10W.

tereck

U need that little motor. U can adjust to if u like. Is always good to clean it

saulgs430

I had the same problem in my 01 gs430 it would hesitate so much i changed spark plugs coil packs everything and still the same thing i solved the problem by cleaning the MAF sensor with a kit sold at walmart it comes with 2 sparys one for MAF and the other is throttle body cleaner i removed MAF sprayed it with that stuff them removed throttle body and spray it with cleaner followed by some brushing after all that my car was back at it. Sometimes its the simple things that affect the whole car.goodluck to you!

Brotherbob

One of the first things I did was to clean the MAF and TB. I really think the throttle motor is going bad it even makes a buzzing sound now. I'll report back once I change it out and get the car good and hot.

On a side note yes I have installed some parts on the car that otherwise were good however its still cheaper than having the dealer install any single one of them collectively! No harm no foul, cheaper than a car payment.

Thanks for the input and help,
BB

Brotherbob

Ok boys....

I replaced the entire throttle body.
I still have the same problem but not throwing any codes......just a little stumble from a dead stop or when turning it hesitates and stumbles.

I'm going to replace the fuel pump even though it ohms out fine...

I'm out of other ideas.

I drive this car 108 miles a day, it drives good , its comfortable and I like it. I'm not done yet.
Just to update-
New filter / sock on the FP in the tank.
New PPS
NEW TPS
New Throttle control motor.
Used Throttle body
New plugs
Cleaned the VVT oil filter.
Run Super unleaded fuel
4 new Denszo O2 sensors
same problem but no codes.
Bob.

Brotherbob

I gave up and took it to a Lexus specialist. I'll report back once I know more.
BB

Brotherbob

Okay boys and girls saddle up and listen real good , you may learn something.
After all the guessing and part swapping it was............


..
.

.
.
.

.
.
.Drumroll....

It was the air intake tube between the mass air flow sensor and the throttle body, the bottom of it was rotten and sucking air. The part was 134.00 via Amazon and she runs like new with no codes.


I do have a complete throttle body with all sensors as a known good one up for grabs and a known good Pedal Position Sensor also that's good so make me an offer and I'll ship it out to some other poor soul who cant figure out why his Lex dont act right!

Problem solved- I'm good with it and learned what not to do....now get on you high horse and tell me you told me it was that part or how I should have or would have as a armchair quarterback!LOL!