Tony

Hey CL owners that own the GS400 can you look at your RPM the next time you drive and tell me if your car idles at 425 rpm when the shifter is in drive and the brakes are on. Mine drops from 725 to 425 and kind of shakes the car and idles rough. If I turn on the AC its fine because the rpm goes to 500 in the drive mode and brakes on. If I put it in neutral the car goes to 725 with no shaking at all.

Please tell me if your cars do the same thing if not Ill take it in for service.

Thanks

Tony

JYOO

Mine does that too, gets real low and starts shakin a tiny bit.
Sometimes at stoplights i give it a lil gas while holding the brake.

///MDex

I have this issue intermittently. I think its been discussed at length, and it was hypothesized that is was the TPS, Throttle Position Sensor, but not positive that it is the absolute culprit.

bitkahuna

iTrader: (20)

No dip here. I think it's about 750rpm all the time.

Maybe affects older GS?

cyclemax

My 98 with only 18K does it also. I was a bit surprised it idled rougher than the Maxima it replaced, which cost half the money.

Ag02M5

Already been to Lexus with this...set to idle at a very low rpm for emissions purposes...I tried to get him to reset it higher but he said that they can't do anything about it unless it is out of spec...a spec that is really low.

Late.

Tony

AGgs400 Ive got an appointment to go to the dealer on Friday, the service person said that this is pretty common on the GS cars but I wonder why? I figured a lexus should idle dam smooth for the amount of money we pay for them. Im going to really hammer them to set the rpm higher maybe 100 rpms higher.

Ill let you guys know.

Anyone else out there experiencing the same thing please post. I have a 99 GS400 with 16000k miles.

Tony

Tony

By the way does anyone out there know how to set the rpms higher if the dealer wont do it? I figure we can do it our selves and set it about 75-100 rpms higher and resolve this problem.

I wish I had the repair manual.

Tony

JacobT

I've been to the dealer for the same reason. Was told the rpm could not be reset. It's control by the ECU unless you reflashed the ECU firmware

If you just keep your AC on all the time, the problem's fixed

Ag02M5

I got the exact same answer as JacobT...I think we are just SOL.

QBranchCars

I echo Jacob's response. I talked at length with my Lexus master tech. That's the way it is, and the dealerships can't even do anything. If your car doesn't stall, no worry, at least that's the corporate line.

aristo400

My 1998 GS400 with 59k does the same thing. Idle at about 450rpms in drive. The car does shake slightly so I now have a habit of putting the trans in neutral at stop lights. Probably a bad habit now. I agree that changing the idle RPM is going to be difficult since it's all computer controlled these days.

itsallgood

I had the same problem as you guys had, I kept taking my car back because it would idle rough during stops, sometimes it would die out. After a few visits and some harsh words to the GM, they did sometihing to the ECU and changed the TPS, since then no problems.

If the dealer keeps saying that its normal, don't believe them its not. The reason for the low idle is something to do with the emmision law. But the low idle problem only effects a small percentage of the Lexus cars, that's why there's no recall to fix the problem that some of us has.

I think if you have them change the TPS you should have no more problems...

Tony

Itsallgood what is TPS Im taking my car in tommorrow to get it checked out but I would like to know what TPS means.

Thanks

Tony

///MDex