LexusGS400

Ok, so i took my car into the Lexus dealership and told them that my car idles very low and while coming to a stop it has stalled and the only way to keep the car from being very rough at idle is to have the ac on. Well I went to pick my car up because they said it was ready and bam, THEY INSTALLED AN ENITIRE NEW THROTTLE BODY. Guys, what a difference. The car idles like it should, you can't even tell the car is on while in drive at a light, the car is much quicker to respond to me gunning it since the throttle body is brand new. I guess there was a service bulletin or a recall for the low idle issue because another dealership is also replacing throttle bodies as a cure to the issue. I have to talked to 3 other owners at the dealership who had the same issue and had the thottle body replaced and they say there car is like night and day still after a month. I am in shock to how quick and responsive my car is now. They replaced the throttle body and the Mass Air Flow sensor. Good luck to everyone.

tomtnc

I'm glad they got it figured out for you.

How can you be sure it was the throttle body if they replaced both the throttle body and mass airflow sensor? These are two different parts located in two different locations on the intake tract.

fireballs gs400

maybe the lexus dealer i use can get a fax perhaps, maybe i can get a new part i don't need yet for free.

SLVRGS

Weird I had that problem with my 1st generation, a while ago and it turned out to be my MAF sensor was put together wrong, it had a gap or somethin and was sucking in too much air, and yesterday my car started to do what you guys were describing and turned my climate control on and it idled perfect, don't know what my issue is but at least I have an idean, and if I decide to but a 2nd generation I know what to look for.

BananaGS

Please post the exact part number that they had replace on your car (on the receipt)

I had my throttle body replace last week, didn't make any different, still low idle.

Anh

GSquicksilver

banana,

he got his MAF replaced as well. so could it be the MAF afterall? i really don't know man, i popped my MAF out and i checked it out. it was clean, no sludge at all, yet m car idles perfect sometimes and weird at times depending on weather.

girvan

If they used a shotgun and installed a whole new engine I guess they'd fix the problem too. I'm glad they fixed your car, but we all pay for dumb mechanics in the cost of our cars. So was it the throttle position sensor, the accelerator position sensors, or the various stop screw or sensor alignment settings? Who cares, charge it to Lexus warranty and let everyone else do the same for a quarter turn of a screwdriver. Keeps the dump mechanics employed and saves time reading the manual..

Sorry I forgot about the broken MAF. Strange how all these parts could be broken That's another $300 for the dealer from Lexus.

GS4spinnin

Hey do you have the SRT ECU?

///MDex

I hope you found the cure, but I doubt it as well.

I bet when the ECU was reset, you are seeing/feeling the temporary effects of the RESET. I HOPE I'm wrong, but..........

JacobT

I just got my TPS replaced at dealership. On my way back home, I turned off AC and gave it a test. Still idle around 500 rpm but seemed a lot smoother now

dabiddle

Hi guys--been readng the posts about low idle problems. I read a lot about the issue with my 98 GS400, which died at idle especially on hot days after freeway driving. Anyway, they simply adjusted the TSS (throttle sensor switch, I believe), which done by merely turning a screw inside the front of the TB. They turned it up 100 rpms and now its just fine! Hope this helps. There used to be some DIY posts in this forum about how to do this.

Synergy

post Lexus part numbers please...

GSquicksilver

dabiddle,

where exactly did they adjust the screw? don't tell me it's the throttle stop screw.

twenty1

i don't know if i'm posting this problem in the right spot. if i'm not, please forgive me. anyway, the check engine light of my 98 gs4 came on saturday afternoon, and was on all day late saturday afternoon until mid afternoon sunday. i had turned the car off, and when i came out later and turned it on, it was gone. it was about 75-80 degrees then. our first genuinely warm day in mn so far. today, it was 90. late afternoon
today check engine light came on. as i left target and was pulling out the parking lot, the car cut out. i started it back up again, and i pulled into a parking lot, and noticed that it was running at really low idle rpm 250-500. it was on the verge of cutting out again, but i turned the car off. i was on the phone with lexus service at the time. upon restarting, i was having the same idle problem, but the car didn't cut out for the remainder of my drive home (about 1.5 miles). i guess i'm kinda inferring that maybe this is heat related. maybe it's just a coincidence. couple of things that i want to bounce off of you guys/gals:

1) i can't get my car in to service until this thursday. lexus service can't provide me a loaner, or guarantee they can look at it until then either. they say that i can have it towed in now, or drive it until then. it's up to me. what do you think that i should do?

2) i bought the car with about 45000 miles on it. it now has about 85000 miles on it, and is still under cpo. however, the only things that i have done to it service wise are oil change, air filter change (k&n) and tire rotation. is there anything that i'm overlooking as far as service that may provide them with ammo to not honor the warranty? the services i have had done were done at the local toyota dealership. i had planned on doing the 90k service (or whichever one is the one where they replace the timing belt, water pump, etc) when it got to 90k.

let me know. and of course, i'll keep you all posted.

twenty1

check engine light went off. i was about halfway full of gas. i was previously using 93 octane gas from holiday (local place). upon futher review, i think it's an ethanol/gas mix. would that have anything to do with it? anyway, i filled back up with 92 octane gas, and when i turned the car back on, light was gone.