95/96 Ls400 Low Idle, Engine Dies And Jerking Thre

[rm_corley]

All,

I originally entered a post "95 LS400 TSB EG000396", but after finding this thread wanted to get on the band wagon. I have a 95 LS400 with 48,500 miles that has begun giving me problems. The course of events are as follows:

1 - Began experiencing "off throttle shock" and occasional stalling followed by a reluctance to start. Car would start after 30 minutes or more. But, car was not necessarily "warmed up" to operating temperature.

2 - Got a MIL with flashing TRAC light.

3 - OBDII scanner indicated ECT sensor faulty, but subsequently, following my Lexus shop manual, ECT sensor checked SAT.

4 - Checked wiring harness and all checked SAT.

5 - Tucked tail and took my car to Lexus. They pulled the same MIL code = ECT sensor. Lexus told me the ECT sensor "is the fix".

6 - Changed ECT sensor.

7 - Got a MIL with flashing TRAC light.

8 - OBDII scanner indicated ECT sensor fault.

9 - Car has deteriorated in ability to stay running when off-throttle, experiences dramatic off-throttle shock at even low speeds and shutters with constant throttle at times. It idles at a very low rpm and stalls if not coached with the accelerator. Once stalled, it is difficult to start - even after an hour.

Is this a classis ECU issue? My LS has ECU 89961-50220. All underhood connections, fittings, plugs, fluids, etc. are in SAT condition.

I have seen reference that TSB EG00396 may be honored by Lexus. If so, by which dealer/service centers? The local dealer in my current locale has proven useless - even after the ECT sensor change.

New news - Lexus USA has stated they would entertain a "good faith" remedy once I'm back in the states. I'm on Guam until Aug05.

HELP, please.

Robert

[95LS400Bob]

Well, guess what I found? An admission that Lexus knew of the dying problem all along. This is a totally different TSB than I found before. This one fits the 95 problem to a T.

http://www.clublexus.com/forums/attachment...achmentid=60660

And that is EXACTLY what the car does. Extremely low idle to the point of the engine dying if a little strain ( such as turning the steering wheel) is put on the engine.

Of course the TSB is for 1996's..not 1995's..but it is the same dealio.

[LEGENDICON]

Well, guess what I found? An admission that Lexus knew of the dying problem all along. This is a totally different TSB than I found before. This one fits the 95 problem to a T.

http://www.clublexus.com/forums/attachment...achmentid=60660

And that is EXACTLY what the car does. Extremely low idle to the point of the engine dying if a little strain ( such as turning the steering wheel) is put on the engine.

Of course the TSB is for 1996's..not 1995's..but it is the same dealio.

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Hey there, for some reason i cant open the site you posted, also i am the guy with the 93 Ls400 with the same problem as you guys, do the site give any insite on how to fix the problem? if yes can you relay them to me thanks

[nc211]

It just says to replace the ecu unit, like mentioned above.

[95LS400Bob]

You need Adobe reader to view. It's a pdf file. TSB Lexus issued for 1996 that states "Early production vehicles may experience and engine idle speed reduction just before stopping the vehicle after a continuous long drive. To correct this condition, the ECM logic has been changed."

While this is for early 1996 models...you can bet 1995's were affected too.

[TexLexus]

Well,

I wonder if I'm going to have the same problem soon, I have a flashing trac light that I cannot extinguish and I also have an amber engine light (the light is in the shape of an engine)

Are these lights related to one another? and is this the same symptom than everyones?

I got a 95 LS400 with 88000 miles.

Texlexus

[yoichisoma]

Hi,

I have a 1995 LS400 with 105k mi. I had the dying engine after long freeway driving. I sent ECU to Car and Truck Electronics which did not solve the problem. I cleaned the throttle body completely by taking it off the vehicle. I have since not had any low idle or dying. The lowest it will go is 550 which is within the 600 plus or minus 50 which is the "normal" per the Lexus Repair Manual. at partial throttle and sudden release of throttle, the engine is abrupt. this is my new issue and I feel that there is a vacuum leak somewhere.

Yo

[flash213]

Update. I just drove 2400 highway miles with a 89661-50224 ECU (used) and did not have a single idle problem. I have not changed the wires or plugs nor cleaned the throttle body. The ECU is the only change in my car which has fixed the problem to this point. Hope this helps.

[95LS400Bob]

Hi,

I have a 1995 LS400 with 105k mi. I had the dying engine after long freeway driving.  I sent ECU to Car and Truck Electronics which did not solve the problem.  I cleaned the throttle body completely by taking it off the vehicle.  I have since not had any low idle or dying.  The lowest it will go is 550 which is within the 600 plus or minus 50 which is the "normal" per the Lexus Repair Manual.  at partial throttle and sudden release of throttle, the engine is abrupt.  this is my new issue and I feel that there is a vacuum leak somewhere.

Yo

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I have one question. When your Lexus would die after the long freeway drive....would it restart immediately and the problem go away till the next freeway drive? I cannot see how restarting the car would solve the issue..even temporarily....if it were a dirty throttle body.

But if your answer is yes...I am more than willing to pull the throttle body off and clean it

[nc211]

Hi,

I have a 1995 LS400 with 105k mi. I had the dying engine after long freeway driving.  I sent ECU to Car and Truck Electronics which did not solve the problem.  I cleaned the throttle body completely by taking it off the vehicle.  I have since not had any low idle or dying.  The lowest it will go is 550 which is within the 600 plus or minus 50 which is the "normal" per the Lexus Repair Manual.  at partial throttle and sudden release of throttle, the engine is abrupt.  this is my new issue and I feel that there is a vacuum leak somewhere.

Yo

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That too is the ECM unit flaw. Is it around 40 mph +/-, take your foot off gas, car buckles around a bit? If so, it's the ECM unit. My 95 did exactly that and I made the dealer eat the repair under thie"window warranty", you know, that 90 day / 3,000 mile thing they do. It fixed the problem and haven't had it since. It's been a year since the repair....no problems.

It appears to me on this EXCELLENT thread 95LSBOB started that two problems act together to create one crappy result. A dirty intake, and a bad ecm unit. I've never experienced the low idle issue, but did have the "Off throttle shock" symptom. My air intake is clean, always has been. And after reading this thread....you can bet it's gonna stay clean too!! ;)

great post ls400bob!

[95LS400Bob]

I am sooo tempted to take a shot at this: http://cgi.ebay.com/ebaymotors/ws/eBayISAP...sspagename=WDVW

[LEGENDICON]

I am sooo tempted to take a shot at this:  http://cgi.ebay.com/ebaymotors/ws/eBayISAP...sspagename=WDVW

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hey bob I just called the # on the ebay auction , let me tell ya , there good people that seem like they know what there talking about, he knew my problem and said he had a solution, if you didnt call i would reccommend you do. and hey thanks for posting that site. I will post my results if i send him my comp.

[95LS400Bob]

I just happened to stumble upon that auction last night. Hope he fixes it. Are you having the "dying" problem?

[morg96ls400]

Hey i ordered a rebuilt ECU from that guy on ebay, I just called him up a couple days ago and ordered over the phone for the part number (xxxxx-xx303) which he had one in stock. It should be arriving sometime next week I am going to install myself and i'll let you know how it goes.

Thanks for the good info

ps: ECU's are plug and play, right?

[95LS400Bob]

Yes they are plug and play. But disconnect the battery first before you do anything.

[morg96ls400]

Yes they are plug and play. But disconnect the battery first before you do anything.

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Do all ECU's support ECT? Or do they have to be programmed to enable that?

[95LS400Bob]

All I can tell you is that there is not a different part number ECU called for with or without ect, so it either supports it as is or has to be programmed. I would bet it supports as is.

[morg96ls400]

Here's an update:

I received the rebuilt ECU for my 96, took 2 hrs to install (removing glovebox and other hard to get to screws and bolts. Then drove it on a 2hr freeway drive non-stop, got off the freeway and braked very hard to a stop...tach stayed at 600-650!

So it seems the ecu did the trick, if anyone needs help on how to remove the glovebox/ecu I can walk you through it.

[Jacob]

morg96ls400,

Do you have to send them your old ecu?

Thanks

[95LS400Bob]

I think he had a 302 and they had a 303 in stock so they sent him that one.

[morg96ls400]

Yeah I had a 302 and they sent me a 303, there was no core charge nor did I have to send in my old ECU

[Jacob]

I think he had a 302 and they had a 303 in stock so they sent him that one.

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Yeah I had a 302 and they sent me a 303, there was no core charge nor did I have to send in my old ECU

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That's cool

[95LS400Bob]

I am going to call these guys tomorrow. If they will work out a trade deal (trade my cali ecu for a 49 state ecu rebuilt) then I am going to try it.

[95LS400Bob]

I called on the Ebay ad and talked to the tech guy. He had 89661-50220 and 50221's in stock but did not have the latest 50224 ecu. He said he would check, rebuild and reprogram my existing ECU (50221) for the $99.95 plus $25 shipping. He said they get this done and ship the same day they receive the ecu.

To buy an ecu outright was $395.

I'll let you know if this works.

[Jacob]

I called on the Ebay ad and talked to the tech guy. He had 89661-50220 and 50221's in stock but did not have the latest 50224 ecu.  He said he would check, rebuild and reprogram my existing ECU (50221) for the $99.95 plus $25 shipping. He said they get this done and ship the same day they receive the ecu.

To buy an ecu outright was $395.

I'll let you know if this works.

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That’s not bad if they ship it next business day.