BananaGS

Anyone here good at writting a letter to Lexus? we need to write a letter to lexus, and ask them to get their master tech to work on this. There must be a solution for this problem somewhere.

Maybe clublexus can collect name, and tel# of the people that effect by this problem and send it to lexus corp. since everyone here trust CL to keep those number right? I can collect the number too, but I prefer not to do it myself.

Lexus had changed out my TPS, TPS assembly,clean this and that, still no solution yet. Lexus must have some head tech guru some where that can figure this out, we just have to make sure they hear our message. My Lexus is very nice, he works with me, but he said he is at an deadend, there is no error log in my car, he does not know what to replace any more, since they have to claim all the repair warranty to Lexus, he can't just randomly replace thing. (even they replaced the TPS sensor for me just to try out per the comments of the folks here, but that still does not fix the problem)

I don't want this problem to get worst when I am out of warranty. what do you guy think?

I know for sure that after the rain (high water humidity level in the air), I never have this problem.

Let put an end to this problem, I am afraid of driving my pimp car and it shakes, dies on me, I have to keep my AC on to raise the rpm up. This is NUTz

Anh

BananaGS

a quick search show a numberous description on this problem, BUT NO REAL or PERMANENT solution. you can read all the old posts here, just a small set. What happen if my car get more miles w/o fixing this problem, I will be out of warrantly, and the low idling get worst. And lexus want $5K to replace some part to fix this, that would SUX big time.

https://www.clublexus.com/forums/sho...threadid=73557
https://www.clublexus.com/forums/sho...threadid=56598
https://www.clublexus.com/forums/sho...threadid=62722
https://www.clublexus.com/forums/sho...threadid=50177
https://www.clublexus.com/forums/sho...threadid=45441
https://www.clublexus.com/forums/sho...threadid=56410


I know my car is NOT stock anymore, but there are members that have stock car and experience the same problem. The worst part is, the intelligent built-in to the main ECU does NOT log any error at all.

PHML

iTrader: (33)

What's the normal idle (RPM) range?

BananaGS

Normal range should be at 600 or higher (this is w/o AC) (3rd mark on the tach), my rpm needle sit at the 2 or 2.5 mark, as 400rpm.

this is my email "got_rice76@yahoo.com" , i've been around this site for a long time, if you trust me, send me your name, what city state you are in, year of your car, and tel#, I can compile a list.

or any of the clublexus moderator volunteer to keep this list should be fine. I want to attach this list with the letter to lexus. Hopefully, Lexus will put this problem in a TSB (technical service bulletin), as long as we have enough people report this problem, it will be come a TSB.

salimshah

I had ONE instance of low idle (right after some hard driving) and the engine stalled at the traffic light. 98GS400 started right back and everything was normal. Currently with 37K miles, ther is no stalling/idlling problem.

Not sure about the following comment: My understanding is that a DEALER would not mess with idlling setting due to emission issues.

How about a set screw mod to pull the throttle a tad?

Salim

bitkahuna

iTrader: (20)

Of those people who have idle problems, who has an aftermarket intake, and which brand?

BananaGS

I have RMM instake with SRT ECU, I made a bypass connector, this weekend, I will plug in the bypass connector to test out if this make any different, I have an o2 meter, my running mix is still good (13.4:1) under acceleration.
This is my observation: (I've take note every day for the last 2 months on this BS.
Just to clarify: I don't have low idle all the time, only when it is dry in the air,
if it is humid outside, no low idle problem, amazing, we had a whole week of rain here in TX, and my car run great, as soon as the sun come out, the low idle comes back. My local Lexus has no problem recreate this, but they don't know what to replace, there is no indication of what is wrong, the low idle happen within a year, I added SRT ECU and the Torque master plug, so these maybe the cause, but then someone here posted that they have a stock car, and have the same problem too, so now I ponder what cause this, beside, the car should be able to compensate and adjust the idle speed by itself, that is why your rpm is higher in the morning, when the engine is not warm up yet, the computer control the bypass valve to increase the rpm, why can't it increase the rpm when the engine already warm up. I am sure Lexus master tech should be able to tell what ECU or sensors control the engine speed in D, with engine is fully warm up, light load (braking at traffic light) You can feel the car is shaking at traffic stop, because the engine is too low

The car dies on me only once this year, when I was rolling 5-10mph in traffic, I think the idle was too low then, could not keep up with the loading. It starts right up after that.

Salim, I was thinking about adjusting the throttle cable, tighten it it more (I should not have to do this, since the idle is electronically controlled, but, this may help a bit, I tried this before lexus replace my TPS and the TSP assembly, I need to try this again since they had reset the cable since)



I can supply all the symptoms and things that I've noticed, but I am not the best english letter writer, can someone help me out in drafting a letter with the symptoms that all of us are getting to lexus corp?


Anh

Synergy

I have had TPS and sensors changed out and I too still experience this BS. My dealer has told me that they will take the car back again to try and get it right. I am going to bring it back in a week or so to see what they can do. I am fed up with this already and think a letter is in order from the group...

tinygs

Ive seen this topic thrown around for almost two years. If I remember correctly it was limited to 98-99 models.....

ChrisK

iTrader: (1)

BananaGS,

You could read some of the Toyota technical articles on this site: Auto Shop 101. They should give you a better understanding on what controls what and how. As an example, it actually helped me with adjusting the throttle cable to achieve smoother shifts on SC400. For all of you wandering why I did this, at one time I had problems with my eninge stalling and I was messing with different things without understanding on what will this cause, and I adjusted the throttle cable to the point where the line pressure was too high causing very pronounced shifts.

By the way, the SC400 idle speed is 400 RPMs, but it runs very smoothly.

GSquicksilver

BANANAGS,

i have already written to lexus corp about this issue a few months back. and they called me up telling me that they will discuss with their engineers but i should not expect any response from them. yes, this pisses me off because i believe that THE ENGINEERS THERE DON'T KNOW A FIX EITHER! you guys probably seen my past threads about the BS i've received from the dealerships. longo lexus was probably the best that had tried to help me with my issue and veronne did the best he could. they gave my car an engine decarb and it sorta helped a bit after i reset my ecu. my car idle's around 400 rpm and it is smooth in cold weather, but in hot weather, the shaking comes again. i agree with you bro, we gotta get the lexus execs to hear us about our issue. my car has around 600 miles before my warranty expires.

it is just weird, sometimes at 400 rpm, my car is so smooth, and at times it's not. so i doubt it could be the low rpm that could be causing roughness. has anyone ever thought it could be the engine mounts? cuz i know honda's shake like hell with worn engine mounts. but i dunno, my engine is smooth when shifting into gear, does not give the bad engine mount system of "jerks" so i'm not sure.

i'm thinking of reissuing my letter i have previously wrote to lexus demanding this time i get a response and have them have one of their engineers look at this issue. maybe a bunch of us should get together, bring our cars to the corp office, and have their engineers check it out.

by the way, i bought my GS used, so i never saw the idling speed it idled at when it was brand spankin new. how many of you purchased your gs4 new and what was the idle speed when it was brand new?

bitkahuna

iTrader: (20)

BananaGS - an RMM intake with an SRT ECU? No wonder you've got problems...

Again guys, this engine is complicated. Idle problems can be a combination of bad gas, bad air, a misread of how much air, and probably the phase of the moon (j/k). It seems to me that aftermarket intakes could cause problems, maybe because the MAF (mass airflow), or other sensor might get bad readings.

BananaGS

hey Bit, in constrast with the popular believe, old generation of RMM intake flow rate is almost identical to SRT, the pipe is a bit smaller, but the intake is 30% bigger. So it even out. My O2 monitor tool shows a perfect mixture with the RMM instake and SRT ECU (I don't have the new RMM intake where they don't come with the pipe anymore, my setup is solid and extremly quiet. I am the only one who has this setup here.


My idle problem start to happen recently, like 2 months after I have the SRT ECU put in, and since, it comes and goes. I understand how SRT ECU work every well, it modify the MAP sensor signal, using a simple microprocessor, there is not much to it, by changing this map signal, the car will advance timing to match the map signal. I've been reading alot of document on idling control on Toyota and other car.

The key thing is: this problem comes and goes. My only solid evident is: when it is dry in the air, I see this all the time. when it is humid, NO problem, very consistant. it's sensitive to the air humidity level. And seem to effect 98-99 GS, maybe 00, only, like Jacob said.


GSquicksilver, this time, resend your letter with a list of people that are complaint about this, you will have a very heavy letter. Lexus will have to look at your letter more careful.


I don't care if the car shake a bit, BUT it has died on me in traffic a few times, that is very scary, someone will hit me one of these day, because the car is quiet, my music is up, I did not even realize that the car had died. And It's not funny when driving through the campus (UT), all the ladies is checking out who is driving the car/ or the car itself (who care, I got a gf) and the pimp mobile died, this is totally BAD.

Anh

ChrisK

iTrader: (1)

Do not touch the throttle air by-pass screw.

"On engines equipped with an ECU conrolled ISCV, this throttle air by-pass screw is seated at the factory, and there are no provisions for curb idle adjustement. Idle air is varied by the ECU through control of the ISC Valve position." - page 4 of "21 EFI#2 Air Induction System.pdf" from Auto Shop 101

SLVRGS

I don't know what "writting a leter is" but just bustin ***** about spelling, I had that problem with my 1st generation a month a go, it turns out the MAF was put together wrong, I think since before I bought the car, but when I broke a belt the engine idled all goofy and must have shifted somethin to make it worse, and from there I had my buddy's shop look at it and the computer gave him a MAF problem. Don't know if this could be related to a 2nd generation but it is possible it could have to do with your MAF.