Gumart1

I appreciate the suggestions. The reason I am avoiding bringing the car back to my mechanic is that I was so dissapointed to find out out that the guy who serviced the car lost a bolt and a nut for the engine cover, and left me with so little coolant after the timing belt change that the reservoir was totally empty when I returned to him the next morning. This was the only shop near me that specializes in Lexus, Toyota, and Scion only and is run by a former Lexus Tech. The service tech also admitted to me that he didn't use anti-sieze compound on the spark plug threds...great. I do have a 12 month labor warranty but I bought the parts 3 1/2 months ago from Sewell so I'm not sure how that will work. I will change the thermostat for kicks and refill the coolant tomorrow; I can't imagine a 3 month old water pump being bad, I did get the old parts back, but if they were really clever, perhaps they didn't change my pump and gave me another guy's old one! Today I attached a piece of tubing to the lower outlet on the coolant reservoir and sucked to start the draining, but even with the force of my mouth the coolant wouldn't budge. This doesn't seem right? Wouldn't it flow freely from the bottom and isn't that the route into the engine? Also, I don't understand the relationship to the room temp air from the vents when the heat is on hot and the engine has warmed - does this specifically point to anything?

Bali, I know it is normal at the halfway point, please read my post, I am near the red. I'd love to believe it was just the thermostat, but remember that the coolant won't come out of the bottom of the reservoir even when I tried to attach plastic tubing and forcefully drain it out. Also, I get no heat through the vents even with a hot engine. And, it was an OEM part installed just 2 months ago. Sure, it still could be that, but I'd be surprised. Also, I both fans, the smaller one at the front of the car, and the larger fan after the radiator, work fine.

In June I had a former Lexus Tech who owns an independent shop locally change my timing belt, water pump, idlers, tensioner, spark plugs, fuel filter, coolant resovoir cap, tranny and diff. service on my '98LS. After the service I noticed that the engine temp ran hotter than before (halfway up on the temp gauge). I waited because I thought it might be air in the system and the coolant just needed to circulate. Never got too hot. In July my starter went out. Had that fixed and the car starts great every time. Weather is hotter now, and the car wants to overheat, almost to the red mark but cools when I am moving fast. I'd be surprised if the new water pump or thermostat were bad (and hopefully the tech did install the new part, he did give me the old back). I suspected that the coolant wasn't mixed right, so today I started to drain the coolant. I followed the procedure in the Lexus Shop Manual, removed the resovoir cap and fill cap, and drained the 3 drain plugs under the car which all drained nicely, nearly 2 gallons, BUT, the coolant remained in the resovoir to the top. So I pulled the lower hose from the resovoir, and was surprised that it didn't flow from there. I ran the engine with the heater on high temp to open the heater valve and hopefully pull the coolant out of the resovoir - still didn't budge. Second issue...when the engine was hot, I got no heat from the vents when set to high/hot, just room temp. AC works fine. I did not have this problem before my repairs. When I moved the heating contols to cold and back, I could see that the heater control valve had moved. Not sure where to go from here. I did remove the radiator and cleaned it but it wasn't restricted much at all. I can take the car back to the mechanic but would much prefer to solve this myself. Any ideas?

Thanks for the quick answer DC - I was able to test fit the rim today, and it seemed to touch the caliper when installed properly. Will I need a spacer to keep it from touching? The wheel spun fine, it just seemed a bit tight.

Admittedly I know almost nothing about sizing, but I do know that the bolt pattern is the same. My OEM rims are 15", 15x7. The GS400 rims are 16", 16x8. Will these fit directly without any issues or adjustment, and can I use either the GS recommended 225/55/16 tires or do I need a different size?

First off, a big HELLO to everyone! It's been nearly a year since I've been active here, and it's just great to see so many familiar contributors and also so many new members! Both my LS's (1991 and 1998) have been doing their jobs so well in the past year that I haven't checked in much. I'm in the process of changing a bad 02 sensor on my '98. I couldn't find the universal Denso replacement that worked very well in my '91 last year, so I picked up an "SNG" universal 4-wire sensor from Oxygengeek.com. These are less than $32 each and shipping is free with two or more. Both the Gen. 1 tutorial on Lexls.com and the SNG instructions don't match my color codes on the factory wires. The factory wires are white, blue, black, and black, and the replacement SNG sensor wires are white, white, grey, and black. I understand that there is a signal wire, 2 heater wires, and a ground wire, but I don't know the correct connections. SNG hasn't gotten back to me yet. Any help would be appreciated.

Dan - I wish I had posted earlier about my conversion to Arnott Struts, but I have to say that it has not been a very good experience and I wouldn't recommend them. I converted my damaged air ride to Arnott on all 4 after being told by a Strutmasters rep that my '91 LS will ride like his '96 Maxima with their kit. Well, I was assured by Arnott that the damping force on his conversion kit would be similar to the current air ride. Installation was fairly easy although they did not include any installation instructions. I also noticed that Arnott's shocks were "made in China" but I gave them a chance. After putting 5,000 miles on them, the ride is consistently too harsh in the front and nowhere near the smoothness of the air ride from before. I've also noticed that I cannot put a load of any sort in the back of the car or I will bottom out over bumps. So I have a firm ride that also fails under load. Crazy. I know the problem is with Arnott as I had just replaced most other front end parts including upper and lower control arm bushings, stabilizer bar bushings, stabilizer links, and strut rod cushions. The only variable I have to admit to is that I now have polyurethane UCA bushings but I still don't have faith in Arnott's kit. If I had to convert again, I'd go with Strutmasters, but in Falcon's case, since he is not converting, I would buy the OEM shock from Irontoad, Park Place or Sewell and find an experienced shop to compress the springs.

Leximus - I just saw your post today. I recently converted my struts to Arnott and am very happy, especially for the price. You did well. At the same time I changed many other suspension parts: lower ball joints, upper and lower control arm bushings, stabilizer bar bushings and end links, and strut rods. I had significant wear on them with 250,000 miles. You should check the condition of these other parts, because you'll likely need an alignment after installing the conversions anyway. I didn't want to blame the ride quality soley on the struts if I didn't like them. Arnott claims that their struts are engineered to give a similar damping rate as that of the air struts. Possible, but I found the air ride to be softer and smoother all around. Initially after install I was pretty dissapointed, but then after driving about 100 miles everything seem to soften up and fit into place. Now I feel like I'm driving a new LS. It was easy to change them (a little more work on the rears). PM me if you have any specific install questions.

Threadcutter - I thought I was &%^&$ but you saved me. It's good to know I'm not the only one that's had this happen. It sounds like SK has had this happen to this or another part in the past too. It gave me the feeling that my 15 year old car is starting to wrinkle like an old man and turn brittle. I guess it's a very weak connection point. I'd really appreciate a photo when you get the chance. Also, do you remember the size of the brass fitting and length that you used? And does the threaded end "self thread" into the plastic open end? Excellent solution. Thanks again.

If my photo doesn't load you can see what I'm talking about in step 9 here: http://www.lexls.com/tutorials/EFI/throttlebody.html In removing the 2 air hoses on my '91LS, the small plastic piece that the hose fits on that attaches to the intake completely broke off :cries: . In the photo the connectors look like an "L", and it is the lower one, the smaller of the two connectors that broke. I tried using a 2-part epoxy and let it sit for several days while I did other work. It snapped right off again when I tried to reconnect the hose. And that's after sticking a screwdriver in the hose to loosen it a bit and lubricating the hose end before attaching. The surface area is so small, I can't see any glue working. The entire replacement part is hundreds of dollars. Any ideas/suggestions?

Arkansawyer thanks for your last post and to the others for your help. Ahhh, I did it at last!!! I was able to jack the motor higher with multiple jacks centered closer to each mount. I also found that there was a point of resistance where the whole car started rising but that by pushing the limits a bit the motor went even higher and there was enough room. The motor was definitely resting against the firewall and had reached it's limit. The passenger side was an extremely tight fit for the new mount. I'm positive I removed all the nuts/bolts from the crossmember but I never did get it to lower. But I was amazed at how much space I had to work with on the driver's side as far as fitting the new mount. I still have to finish assembling everything. My old mounts were very crushed so I expect a nice improvement! Thanks again. By the way, does anyone know the correct torque specs for the 2 nuts and 2 bolts for the crossmember?

95LS400Bob - Great to hear from you! I know it's been awhile, but it appears from your posting that you did lower the crossmember. Here is your original post: "The mounts are indexed so they only go one way. Heat shield is important and must go back in place. Since the motor couldn't go up...that meant the crossmember had to come down...at least a little to give me room to get the mount in. So I loosened the crossmember (17MM deep socket) and let the crossmember lower enough to get the mount in. Then I did the driver side...had to lower the crossmember a little more. Soon as I had both mounts in place...then I tightened the crossmember back up." So I am wondering exactly HOW you loosened the crossmember and if you ran into any issues? I have jacked the engine as high as it will go, and I can see that because the mounts are compressed to different levels that some people might be able to just get them out from raising the engine alone while others cannot.

Well, I've gotten some great replies from some very helpful members here but my crossmember is not budging with 2 nuts and 2 bolts loosened :cries: . I also hit it pretty hard with a block of wood and a hammer. I'm either missing a hidden bolt or it's frozen or I'm doing something else wrong. I have the car on jackstands on its rails, and the engine jacked up almost touching the firewall. If I can't lower the crossmember, I'll give in and remove the submounts, but they aren't very easy to access either. Does anyone have any info or diagrams on the crossmember removal? Thanks again...

Yes, it's quite possible that the pump at the station wasn't calibrated, as Lexirx330 mentioned, with a different shut-off mechanism, that shut off at a different time than before. I did use the same service station, but I might have been at a different pump. I don't top off, so I can see where it's possible that the pump stops but didn't fill it to the same level as before. Oohryry - yes, this is for my '98. I'd love to know exactly how accurate the ECU is, how it works, and what the margin of error is. But I can now understand that the pump is probably what's inaccurate. Hey not bad...24.9mpg average city/highway, A/C on constantly, 233k miles. :D

I had some difficulty reaching the back submount bolts, so I decided to raise the engine to see how far it goes. I managed to get it pretty high, and was able to get the driver's side mount out! I'm so excited, because the old one was soooo compressed. This should make a huge difference! Still can't get the passenger side out, probably because it's not as compressed. So I loosened the 4 nuts and 4 bolts on the crossmember. The nuts and bolts are somewhat loose (didn't want to go too far) but the crossmember hasn't dropped at all. I'd like to know if I am missing any nuts/bolts or if I have to hit the crossmember with a rubber hammer to break it free? I want to lower it a safe distance but I'm unsure what the limit is. I assume I am safe as long as the engine is being supported by the jack. I have read the other threads on dropping the crossmember but still need help over this hill if anyone else has done this job. Thanks!

I reset my trip odometer and tank and trip mpg settings, and refilled my tank to full. Drove it 398.1 miles and filled it up today. It took 17.829 gallons. Comes to 22.3mpg. My ECU tells me that total mpg for the tank at fillup was 24.9mpg. Why the difference, and which is correct?

That's an AMAZING list SK. Congrats on all your efforts. Any new pics? This may be a dumb question but how do I convert KM into miles? "So as you can see for a very high mileage (too me) car that drives and is reliable as a 60 000km version this is a shining star." I couldn't agree more. That is why I just bought another '98LS! Yep, I couldn't stay away. I may go down as the guy on the forum who keeps buying and selling these, but it is a learning experience for me and I have to say it has given me a good perspective on a few things. First, mileage has significance but is not NEARLY as important as maintenance and driving habits. And second, even with neglect, some of these cars still hold up very well! My new '98 has 233,000 miles. It is black with tan leather and chrome wheels and Nakamichi, but no NAV, HID or wood steering wheel/shifter. The previous owner bought it CPO with 42k miles and was a dental equipment salesman. He averaged about 45k miles each year for the last 4 years! He had a terrible maintanance history and did NOT go to the Dealer. Many people would walk away from this, but I've driven too many to know the good from bad. It drove like a dream, better than my last '98 with 100k miles. I've been driving it for a couple of weeks and have no immediate problems other than needing brakework. No leaks to be found and I just drove a tankful and averaged 25mpg exactly. I agree that these are the best years visually and mechanically (If you remember to change the timing belt before it breaks).

I am in the middle of changing out my motor mounts and need some quick advice. First of all, thanks 95LSBOB for a great write-up, but thank you Glenmore for all your assistance and PM's! If you are out there, please feel free to chime in. I have all the nuts off the old mounts. The Driver's side was hard to access but not all that bad with the proper extensions. I'm about to raise the engine using a small cut of a 2x4 across the oil pan, as far to the rear of the oil pan that I can place it. From what I can see, the crossmember is held by 4 nuts, 2 on each side near the outer part, and 4 bolts near the center of the crossmember. Do I remove the bolts entirely and loosen the nuts visually? What happens if I over-loosen the crossmember? What's the best way to do this? Has anyone with a 90-94LS successfully changed the mounts without removing the submounts?

No one deserves it more. Congratulations Blake!!!

Walt - You don't need to remove the throttle body for the replacement. I'm replacing my TPS sensor and was able to get some Ohmmeter readings and do the test/adjustment properly. I've gotten help from a few members here. I'll add some pics later, but I used micro alligator clips that I purchased at Radio Shack and attached them to the two correct leads on the sensor (IDL and E2 if I remember). There are the two leads on the sensor that are nearest the driver's side when the sensor is installed. Once the alligator clips were in place, I loosely installed the sensor, then I used 14 gauge electrical wire and slipped it into the opening in the alligator clips. I attached new alligator clips to the open wires, then attached my ohmeter leads right into these clips. Sounds complicated but it wasn't. It's a VERY tight fit and I found this method to work just fine to get good readings. Melhullica described it accurately except you want to use a .40 feeler gauge when installing the new sensor. Also, according to the shop manual, you turn the sensor clockwise until there is NO resistance, and then tighten it down. Melhullica - In your post you said that you turn the TPS until you lose continuity, not resistance. If that's true, that would mean I'd have a reading of infinity on my ohmmeter. Now the ironic thing is that I am stuck right now as I install my new sensor because that's exactly what's happening. I go from about 8 ohms of resistance and then I lose continuity suddenly as I turn the TPS. But this is contradictory to the shop manual test which says turn it until there is no resistance. Just wondering where you found your info and if it's correct. According to the service manual, once zero resistance is acheived you are supposed to insert a .85 feeler gauge and have no continuity (infinity) whereas with the .40 you do have continuity with zero resistance. Walt - I purchased my new TPS from Carey at Park Place Lexus (Newlexusparts.com) for about $75 shipped and it was the lowest price I can find. Also it was shipped within 24 hours. I'll get some pics added later.

I did have the codes read as I mentioned in my earlier posts and I have a code 41. According to prior posts this points to the TPS itself or the wiring to the TPS or the ECU. That is why I set out to troubleshoot instead of throwing parts at it. Thanks Threadcutter and others for the help - I plan to order the part today it is about $110 shipped for my '91. Not sure if I should replace the sub-sensor as well ($75) because it is just as old as the main TPS, even if it doesn't throw a code? Does anyone here know exactly what the sub-sensor does? All I know is that it is related to the Traction Control as I understand the sub-sensor only exists on models with this option. I'll report if the problem is fixed. Besides my CEL with code 41 the car starts, idles, and runs great.

I am guessing it is the throttle position sensor itself but wanted to share my readings. I just finished testing the resistance on the sensor and I have to say it is not easy to get to. I had to remove the sensor first (marking the location of the housing). Then I attached micro alligator clips to the correct terminals. After reinstalling the housing, I slipped some flexible electrical wire into the alligator clip ends, and then attached my ohmmeter leads to the wires. This was the only way to clearly see the terminals to make sure I had it right. There are 5 different test for resistance between 4 different terminals. 3 of my tests were perfectly within specs. However the two tests that had me connect terminals IDL and E2 gave me NO reading at all. I repeated the test to make sure I had the contacts in place. I also had the correct thickness gauges to insert between the throttle stop screw and stop lever. I am surprised because I expected to have too little resistance, telling me the sensor was bad but no reading? Do you think that one terminal is bad or somehow broken? Is this a possibility or did I do something wrong? I'd love to conclude that I indeed have a bad TPS from this test. What do you think? Threadcutter, just from looking at the diagram of the innards of the TPS I can see now what you have been saying, that it is just a simple potentiometer. In that case I'm betting that my one terminal (IDL) is somehow broken inside or not reacting. Can the housing be removed to access this? I don't see that it is removeable.

Ross and Threadcutter - Thanks for your input. Here is a post from member Obergc (Curt) that I found helpful: "A code 41 for a 93 indicates a bad throttle position sensor CIRCUIT which includes the throttle position sensor, part of the ECM since it supplies excitation voltage for the sensor and all of the interconnecting wiring between the throttle position sensor and the ECM. This should be an easy problem to troubleshoot if you have a digital voltmeter. Your 94 might be different from the 93 but for a 93, the throttle position sensor has 4 wires connected to it. With the Ignition Switch in the Run position, the blue/red wire should have a constant +5V amd the brown wire should show a good ground connection. The yellow wire should have a voltage between 0-5V and it should change smoothly when you move the throttle linkage. The green wire should also show a good ground connection with the throttle at idle position." Now my shop manual only shows testing the actual TPS and not the wiring harness that connects to it. Also the shop manual doesn't mention testing the sub-sensor but I assume the test is the same. So if I understand correctly, to accurately pinpoint the problem I need to test the actual contact leads on the TPS for the correct resistance as well as the the wires from the ECU for the proper voltage, all tests to be made with the ignition on but not running. Ross, are you saying that you can use the test brads to get to the wires from the open end of the harness where it connects to the TPS? Threadcutter - Is the Radio Shack part you are referring to the TPS or the wiring harness? Sorry I am confused here. Do you have a part #? Thanks again for your input.

Purchased the '91 this year and AC has always blown warm air. No codes stored with AC test. Former owner had it to Lexus in 8/01 and had dye run through system as well as 3 cans of R12. Owner brought the car back and Tech replaced leaking O-ring seals at the expansion valve. Rechecked and everything OK. 3 weeks later warm air. Lexus says Evaporator is OK but found leak at high and low side AC lines. Replaced both hoses, charged system and added dye. No other leaks found. Parts replaced were: discharge hose, suction hose, O-ring kit (same part# replaced a month before), and bulb. Also on the receipt are 4 cans or R134. 1 year later in 2002 the car was brought to a Union 76 Station where they noted under safety recommendations: "AC Compressor (seized), also expansion valve, receiver drier, complete system flush and oil charge & recharge". Coming into this forum I knew almost nothing. Yet I have been able to fix and replace almost everything that is mentioned on the forum as long as there is a tutorial or discussion. I have no background in AC and truthfully can't even locate most of these parts. I'd love to troubleshoot myself but don't know where to begin. I'm assuming Lexus converted to R134 but I never found the word "conversion" nor do I know how to check. The fan speeds work great as does my heater and LCD display. Any advice would be enormously appreciated.

Ross - Exactly where is the TPS switch? I think I remember you mentioned that there is more to check or replace than just the sensors. Do you know how to check the wiring from the connector back to the ECU, or can the problem be the ECU itself? I am throwing a code 41 like LScott400 and was sorry to hear that the replacement TPS did not solve his problem. In doing other improvements not related to the code 41, I have already changed the plugs, wires, caps, rotors, fuel filter, cleaned the TB, air filter, and main O2 sensors. Though I can't pinpoint which had the greatest effect, I can definitely say that the car starts faster and has more power than ever before. Throttle response is excellent. I am stunned at how well it runs at 253k miles. I have a slight vibration at idle that I suspect is one or both motor mounts which I am attacking next. I throw a code immediately after resetting the ECU or disconnecting the battery. 41 is the only code. In addition, I have two TPS sensors, apparently because I have traction control. Is one of these a "sub-sensor" and the other the main, and exactly what is the purpose of the second sensor? Finally, I tried to correctly test the sensors following the shop manual/lexls, even used the correct thickness gauges under the throttle stop lever to take my readings, but I could not attach my multimeter to the TPS, even with micro alligator clips. The angle seems impossible. Any tips? Anyone?