yoichisoma

I am following this thread closely. My 1990 LS has no idle, It dies right after start and must keep foot on the gas to keep the engine idling. For now, I turned the screw on the throttle mechanism to keep the plate from closing and allowing it to idle. Now I'm looking for a real fix. Yo

This is a known problem. Replace ECU with updated version. Check dealer for TSB. Also look up LS400bob 's thread on this. Must replace ECU and clean TB while you're at it. Can find junkyard ECU but must be the new version designed to replace original. Do not try to rebuild original. It will not fix the prob. Trust me this is the fix. I have a 95 LS with 148000. No problems now.

Hey, I agree. I've fixed lots of cars with fine bubbles in the fluid when bled. When I bleed the brakes I use a clear plastic hose from a hardware store and poke it through an old oil jug so I can see the quality of the fluid being bled. Fine bubbles in the fluid are likely from the Master cylinder. Just get rebuild kit and rebuild the inside. Good luck. Yo

Hey, If the vibration you are feeling is vibrating the whole cabin-- Like a vibration that causes the passenger seat back and head rest to vibrate, then you need to change the two engine mounts and the transmission mount. Not very easy but I did it. Took a whole day. Unless the check engine light is on it is highly unlikely that anything electronic/ignition is wrong. The engine computer in the 95 can be troublesome. It may cause jerky acceleration/deceleration/shifting. A big jerk can be felt letting off the gas at certain speeds and around the parking lot. It can also stall and have low RPM at Idle. Call around a junkyard for a revised ECU and install that. Get the ECU part number from lexus and do a google to see who has one. It has worked wonders for me. My 95 is so smooth now. I also changed all the suspension arms and shocks up front. Unbeleivable difference. Drum tight. Don't get carried away, but little things can get irritating in this car because you can feel and hear everything. yo

You can search and download and print the repair manual from Toyota Lexus service support site TIS. Cost 10 dollars a day.

Guys, It is worth looking at the TSB on the TIS site. It cost 10 dollars a day to sign in and you can print manuals and look up TSBs. It says exactly which models are affected and exactly what ECU to buy and the dealer will know if the ECU in the TSB has been superceded by another part number. Take that part number and do a google search and you will find wrecking yards that have the exact part. Forgot how to take the glovebox apart, but screws are usually hidden behind plastic caps. It is pretty tight and you will need 1/4 inch rachets and extensions, long 10mm sockets and might be easier if you remove passenger seat for body access unless you are a contortionist. Yo Gold 95 LS400 145k

Try taking a look under the car. The Tranny mount is at the rear of the transmission. the rubber should be supple and the metal brackets should not contact each other. It is pretty cheap anyway so you might as well change it while you've got the car jacked up. Just remember to support the tranny with a smaller jack placed carefully so as not to bend the trans oil pan. 98 is a good year, got the 5 speed and vvti. Fast. Grinding under torque might mean an engine mount as it theoretically might allow the engine to lift on one side and allow metal to metal contact on the engine mount. Yo

The shaft seal can be replaced on the Nippondenso 10PA20c but it is very difficult. Buy the seal at the dealer. You can buy a good rebuild from DENSO the original manufacturer with clutch and magnet for 600 something dollars. It is probably worth it. You might as well try changing the shaft seal once. Give it a try. it's less than a hundred dollars. Yo

The throttle cable that tells the trans how hard to shift was broken on my car causing the trans to think it was at a high throttle level and thus shift fast and hard. Have someone check this cable out. Yo

I think that is the dimmer for the instrument panel. Yo

It's not really hard to fix a/c yourself, but you need a few things like a vacuum pump and guages. A/C shops are not always the best to go to. Some will use poor quality aftermarket rebuilt or non original parts. The quality is poor. They may give you a warranty of one year, but the parts usually only last a year or so. If you have an independent do it, make sure they show you which part is leaking and change that part only plus the required new receiver/drier (about 50dollars). Rarely do two things leak at once. it is probably the evaporator/expansion valve assembly or the compressor shaft seal. Both are expensive. Just don't take the "package deal and the warranty" Take it to a Toyota or Lexus dealer. I always do for all my Toyota/Lexus cars. They don't charge much more than anyone else. Yo

I would not try any leak stopper or ANYTHING for that matter if you like your car. Look under the A/C compressor. If there is a large oil stain it is the compressor. If none of the external hoses are leaking in the engine bay, then it is almost invariably an expansion valve/evaporator leak. I have changed mine on my 90 LS twice. I fiddled around with alternative refrigerants etc in the past and kept on blowing the controller valve on the low side just in front of the firewall $200 plus each time. I wouldn't mess around with anything but the pure simple standard ways of fixing A/C. Oh also go with original dealer parts or DENSO genuine parts. Yo

This is good thread from LS400bob. My 95LS did the same thing. I had the original ECU "rebuilt" but it did not fix the problem. Just to be sure, I looked up the TSB technical service bulletin on TIS (Toyota Service Support website) paid 10dollars for a day pass and looked up the correct part numbers. They have been superceded a few times. It says to change the cruise control computer too, but I did not do that. I took the part number and did a web search for a junkyard ECU and got it for 200 or so I forgot the exact price. A new ECU runs well over a grand. No problems with the car ever since. Yo

Hi folks, First of all, you need to check the sight glass to see if refrigerant is circulating when your compressor is on. If you have guages, hook them up to check the high and low side pressures. The sight glass should be near the front of the radiator and condensor above the drier which is a cylindrical object the size of a large soda can. There should be refrigerant flowing through there with some bubbles. If this is not the case, you probably lost refrigerant. Too many bubbles also means insufficient refrigerant. if insufficient, try charging it temporarily by getting a can of r-134a at the store. 1996 should be r-134a. Be very careful, things are under high pressure and a mistake could cost you your health. If unsure, take it to an a/c shop. If leaking, it is probably a compressor seal, a flexible hose or your evap/expansion valve and it needs to be replaced. Let us know what you find. Yo

Hi folks, I have a 95 LS and had the same problem. Bought a new radiator. As I was changing the radiator out, I found a whole lot of dust and dirt stuck in front of the radiator clogging the air flow. The condensor is in front of the radiator, so it is not visible unless taken apart. I wasted money on a new radiator because the old one could have been simply cleaned off and re-used. I changed it out anyway though. Now everything works fine. Water pumps rarely fail internally. They usually leak when their seals go bad so you can tell. Let us know what happens. Yo

Small point. Probably don't need to bring it up but did you check your battery cables to make sure they're tight? I've done a lot of things in the past only to find that the battery cable was intermittently losing contact. Yo

I had the same problem on my 90 LS, and 93 SC. Check engine light did not come on for weeks and the car would occasionally lose power and stumble for a minuite or so. When the code did finally appear, it was the oxygen sensor on the exhaust. there are two on each side. I think it was the one that is more accessible. Anyway the dealer knew it was a common problem and pointed out which one to change. I did it myself. Make sure you have the perfect wrench or socket to pull it out because it is stuck in there very tight. Avoid stripping the thing. Good luck. Yo

I also had my ECU rebuilt at auto and truck electronics. Off throttle shock was considerably better but not totally resolved. Off ramp stalling did not occur for about a year now, but just the other day, it suddenly happened. It has been running around 400 rpm on the off ramps which is somewhat abnormal. I am going to be writing to Lexus to at least give me a break on the 89661-50224 now superceded by 89661-50225. The problem can be dangerous if an unsuspecting driver happens to encounter it in a tight situation. Yo

Sorry for the delay, I have been out of my mind at work. My LS's original symptoms were exactly as described by 95LS400Bob. Off throttle shock aroud 45, and freeway off ramp stall after long drive with perfect restart performance. I got Car and Truck E. rebuild and Cleaned throttle body. I have since made at least 10 160 mile drives from Redding to S.F. or Sacramento and have never ever had to worry about idle again. I used to have a 90 LS. I think the 95 is quirky because of the attempt to make it fuel efficient. The transmission has strange shift points that is counter intuitive. It shifts up too soon. Anyway, Seems like from some of the threads Lexus will pay for the job if you nag them enough. I also think it is a major safety and liability problem. Yo. 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 ←

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

Sha I have a 95 LS and a 90LS. My 90LS: I changed the radiator 3 years ago because I noticed the auxillary fans kicking on on hot days. I did this because experience with 92 toyota previa van with climbing temp on hot days with relief by turning heater on. that problem was fixed by changing radiator. The fins get brittle after many years and don't transmitt heat well. most of the deterioration occurs on the front of the radiator where you cannot see. It hides behind the A/C condenser. I would change the radiator with genuine parts and red coolant. Pump unlikely bad if not leaking. Thermostat a good idea since it is cheap(probably better to do first). Yo

jeff, what were the symptoms that prompted you to fix the broken EGR pipe? Yo

Hi I have been reading this thread. My car seems to stumble when I let off the gas on partial throttle on a cold start drive. It also stalled off the freeway (this may be unrelated). The car also seems to be abrupt when I let of the gas when driving around town. I was looking for a vacuum leak and came upon this thread. Please advise me if these are symptoms of a crack in the EGR pipe. Yo

Hello, Sorry I was on a trip to Tokyo so I have not been able to respond. I got my ECu back from Auto and Truck Electronics in Fla. I was driving around to test today and it seems that the jerking is quite a bit better but the engine dying out after a long drive issue is still a problem. It did not die on me as I did not go on a long drive, but the idle was very low at aprox 400. It should be around 550 or 600. So Indeed I am perplexed. Should I go for a 89661-50224 or should I seek a new cruise control computer and spark plugs? This is the TSB for "to improve driving smoothness at speeds above 40mph." Nowhere in the TSB does it mention stalling after a freeway drive. Anyway, I am going to change some hardware today including all spark plugs, wires, dist, rotor, and ignition coils (2). Also I got the throttle body off and I am going to clean it. Please, if anybody has solved this issue completely, tell us what you did. Yo

Thanks 95LS400bob now I am motivated to get back into the cold garage and take that baby out. Yo