CKIM

iTrader: (1)

Hello all.

I need some help.
I have '99 GS4 with 115,000 miles on it.
I purchased it CPO w/ 38K miles on it. At 45K the throttle body went out and had it replaced under warranty. From then on i noticed the low idle, and had my car die on my while driving a few times. Lexus replaced my throttle body again at 58K which was about a year and a half ago. I continued to complain about the low idle and how my car was still dying on me. They said they couldn't find anything wrong with my car, so nothing was done. So at 112K my car dies on me again and wouldn't even start one morning, dealership says i need to clean my throttle body...which i got done. Now at 115K , engine lights turn on...and now lexus says my throttle is failing and needs to be replaced. Of course all my warranties are up. I'm not about to pay $1000 for another TB.

If anyone has suggestions I would appreciate it.

Thanks

Chris

rominl

iTrader: (4)

there must be records showing your concerns and all the checkup on the TB before. talk to dealership and that you had problems but it's them who couldn't figure out the problem. if they don't want to do anything, try to talk to lexus corp

koolaidman

off hand i dont remember if its fly by wire but if its not u can adjust the tb cable

chuckb

was the MAF sensor ever replaced? Does it only idle low when lights or AC are off?
too me, raising the idle by tightening the cable is only masking a problem.

VVT-i

1998-2000 GS400 is the first gen of drive by wire.Can you tell me how to adjust the cable on the 99 GS400? When you step on the gas pedal, the tb cable will pull the Accel position sensor and the Accel sensor will send the signal to the ECM, VSC/ABS/TRAC control ECU, Yaw rate sensor, wheel speed sensors and those sub sensors will give the feedback to the ECM.

A: It's o.k to open the throttle wide open because all of the conditions are o.k.

B: No, it's not o.k to the wide open condition because one of the wheel is spinning.

This's just an example of the drive by wire.

CKIM

iTrader: (1)

Thanks for the replies...

Well after running their tests I guess the computer had an error code # P0505 pop up.
So they recommend replacing the TB again. They said something about the computers in the car not getting the throttle body to work w/ the VSC to get my car to idle where it needed to be.

I've talked to corporate a few times and written letters. I called them and they said they would get back to me in a few days. That should be tomorrow. So hopefully they will be able to do something.

Recently i've noticed my low idle problem is different everday. Somedays having the AC will help other days it won't. So its pretty random.
I will try tighening the cable.
But I was also wondering if anyone out there has had this many problems with their TB on a GS400? This would be my 3rd time replacing it in 3 years.


Thanks

98LexusGS

Have you checked the air intake for cracks (even hairline)?

CKIM

iTrader: (1)

New update 9/9/05.

I couldn't find any cracks.
But after a few phone calls to corportate. They agreed to pay half of the bill for the new throttle body. I wasn't in the mood to fight it anymore so i agreed.
The throttle body was replaced and now they are telling me one of my fuel injectors is bad and that it will need to be replaced.
I checked out my car last night after the TB was replaced, but before anything was done with the fuel injectors. The car was the exact same condition as when i first took it in. The same check engine light and the 2 VSC lights, also the car was vibrating heavily as it had been.

How do I figure out if my TB was really bad? It was only installed 2 years ago (maybe 50K miles since.) I'm thinking they misdiagnosed it. Any suggestions on how i can prove it? Because they are sticking to the story that both are bad.

Thanks for you help.

sung35

I don't think Lexus knows the root of the problem, and neither are we. I believe a lot of members here have the same problem as you have. I have a 2000 GS4 and not having the problem yet. However, my RPM at idle no AC or any thing on is always around 400 at the second tick mark. I expect the RPM to be around 550 mark. The car has not die on me yet.

alexulan

Dude that sucks!

They definely misdiagnosed and now you need to ask for your money back and go do a different mechanic.

By the way I also have a 2000 with low idle, NO AC the car dies in stop and go traffic.

Keeping the AC on has been the solution for about two years.

Hope you didn't pay yet or used a credit card.

CANCEL THAT CHECK!

sung35

Oh no. How many mile your car has? My is 52K miles.

CKIM

iTrader: (1)

I've had my car die on me about 6 times while on the road.
I happened on the offramp off the 405 on a on ramp....everywhere.
Its definetly stressful driving a car that could die anytime.

I've tried to fight that with Lexus with no luck.

Anyone know where I can take my old TB and have it checked to see if its still good?
To prove to lexus that they were wrong.

chuckb

you guys know if you turn your lights on it does the same thing as having air on, right?