Leadfoot

I read the book "Zen and the art of Motorcyle maintenance" by Robert M Pirsig years ago and it came back to me recently whilst I was replacing the rotors and pads on my old LS400. I was deeply impressed with the quality of the materials used, the design of the parts and the ease of working on a reasonably complicated piece of machinery. One of the things I found most interesting in the book was the description of gumption traps. You know when you are working on something and stuff starts to go wrong, your bloodpressure rises and the job just seems to get away on you? The solution offered was to have quality tools and hold them for a while and let the quality seep back into you. I know it sounds really new age but I really felt this way working on the lexus. It was really nice to spend the time working on it. Or it could just be that the winter has been long and cold and summer is finally here and I can work outside without freezing to death!

Whilst I utterly respect your opinion Monarch, I think if the guy is keen he can't go wrong if he is cautious, methodical and can follow instructions. If you can use a torque wrench and your brain then you will be fine Grandpa. I also recommend you go spend $10 and get 24hrs of access to download all the workshop manuals and technical service bulletins for your model from http://techinfo.lexus.com/ The instructions on Carl's site are excellent and you can always come back here for help. The bolts will be fairly tight so you need a decent set of tools, breaker bar, sockets, torque wrench etc. Also be prepared to find rubber boots perished, springs broken or missing and therefore it pays to have an alternative method of getting to the spares department to get new parts or have the car off the road until the job is done right. There is a lot of satisfaction from knowing the jobs been done slowly and carefully. However step six in the rotor replacement differs from the workshop manual. The manual says you should torque up three of the wheel nuts before securing the two little screws (one of which was missing on my one!). The wheel nuts have a tapered nose and these centre the disc exactly, you need to look closely otherwise you can introduce an imbalance, something I feel a few people may have fallen foul of on this forum. Once you have done up the screws you just take the nuts off again and continue as instructed. I would recommend that after completing the job you take the car for a careful drive, progressively testing the security of your work, then return to the workshop and jack it back up and make sure everything is spinning freely with out binding ( a tiny amount of drag is OK). Old siezed calipers can be a real pain so you do want to make sure all is as toyota intended. I did all four discs and pads a few weeks ago and the improvement in braking is surprising. My boots on the front caliper pistons were shot so I had to rebuild those, but it wasn't hard and working with lexus quality is a very satisfying experience. Good luck & wear goggles!

Hi Sam, what is happening is not uncommon and is not necessarily a problem either. Below is the toyota Technical service bulletin for our year, mines a 92 as well. They released this because of customers giving them "feedback" on the vibration. It feels like you have driven over a small patch of ripple strip right? Mine only does it when I have been cruising at 1800rpm and accelerate mildly. If I stamp it it never happens, gently never provokes it either. I cannot reproduce it at will, it is only when conditions are "suitable". I think gas quality may have a part to play too. Anyway here is the word from the horses mouth..... "ENGINE EG92–002 OCTOBER 09, 1992 ALL MODELS ENGINE PING REFERENCES IN OWNER’S MANUAL Page 1 of 1 Under certain driving conditions, minor engine ping, also referred to as “spark knock,” is common for high compression engines such as those used in all Lexus models. Do not hesitate to inform customers of the following information included in their Lexus Owner’s Manual: This statement is included in all Lexus Owner’s Manuals on the following pages: MODEL YEAR PAGE ES 250 1990 165 ES 250 1991 171 ES 300 1992 165 ES 300 1993 170 LS 400 1990 166 LS 400 1991 166 LS 400 1992 172 LS 400 1993 192 SC 400 1992 170 SC 400/SC 300 1992 170 SC 400/SC 300 1993 186 Because all Lexus models have knock sensors, the following question may arise: Q) When I hear knocking, does it mean that the knock sensors are not working correctly? A) Engine control systems with knock sensors operate by modifying ignition timing when knocking is detected. In other words, knocking must be present before the control system acts to modify the timing. This is usually noticeable by a short duration of a light knocking noise and is not cause for concern. “If your engine knocks... If you detect heavy knocking, even when using the recommended fuel, or if you hear steady knocking while holding a steady speed on level roads, consult your Lexus dealer. However, now and then, you may notice light knocking for a short time while accelerating or driving up hills. This is no cause for concern.” Since yours sits around alot I bet the gas in your tank is not the best quality anymore. Go for a big drive and run it nearly empty then fill up with the highest octane gas you can find. My 0.02C says its poor gas quality. That is exactly what happens in mine, and I bet yours is no different. It just the ECU working the best timing point out, and it happens to be around 1800rpm 40~50mph typically. Has been happening to me for a year now (crappy UK fuel!) and has not gotten any worse. These cars can make you a bit of a perfectionist (wouldn't you agree NC211?) which is why toyota had to put out the TSB. Hope this helps, Cheers, Leadfoot.

post withdrawn after reading the thread more carefully. soz.

I have a '92 and it sometimes vibrates/shudders under load around 1800 rpm and it is also driving me crazy. However nothing comes up on the diagnostics and everyone in the car says how smooth it is. But something is not right..... I suspect its either the engine mounts (tranny mount refreshed but original engine mounts still working at 162Kmiles) or ignition wires/dizzy/coils or my slightly leaking EGR pipe or maybe the O2 sensors. The cost of fixing these is not worth it for me so I keep running it as is with the minor irritation. However I will do a valve clearance and compression check once the weather gets better (in the UK thats unlikely to happen!) and try and fix the egr. Maybe yours is similar? I have had the car a year and its not gotten any worse, which makes me think its only the ECU ranging the advance on the ignition. When it is under load it can detect detonation and pulls back the advance curve accordingly. I think it just might be normal, however I can detect a faint uneven tremble in the idle, especially when in drive and parked up a slight incline. Comes through the pedal and the shifting stick. However when my wife is in the car and I feel the engine block with my hand, its smooth as silk. A complete mystery. I have felt other engines from the same generation and its no different. One guy thought I was a complete freak for wanting to "touch his engine", another was a taxi driver who said mine was running perfect. His had 240Kmiles. A lexus tech who I questioned said the crank sensor lead can sometimes get worn and this can cause the problem, but mine is fine. Good luck!

Will chip in here with a tip for the best $10 you will ever spend, 24hours of access to http://techinfo.lexus.com/ download the entire 1991 section and you will have a gold mine of info in PDF form. From the 92 manual it states the most likely culprit for long cranking is 1) a bad starter, 2) air conditioning signal circuit 3) engine mechanical Had a look at the aircon section, couldn't make sense of it, basically looks like its implying a problem with the compressor. I have not had a problem with my starter, hopefully someone who has will chip in soon. good luck!

Have to agree with you all, the brake switch is the best thing to check first, likely to be the culprit. I misread the post as thought he was driving and having the trouble, rather than just selecting drive. Hehehe always read the small print????

Is your alternator in good condition? any leaks from the power steering? A low battery voltage can cause things to malfunction. Please check the voltage across the battery terminals with the engine running, anything less than 14.6 volts is bad. You could also investigate the rear wiring loom in the trunk lid. You can search the forum using the terms "broken wire" and read about it. The posts mainly refer to the reverse light, not the brake lights, but it is a known fault with the early cars (they made the looms just that bit too short) and could be a root cause for your problem. Good luck.

Absolutely true, but he did say that the dealer thought it was a sensor. The diagnostic mode in the ECU is more sensitive than the standard running condition (which has not shown a CEL) so might help determine which ones faulty, plus its a really easy thing to try, 5 minutes max. Dealer will fix the problem, I just wanted to give the guy an easy route to maybe get some info to backup the dealers response. Will be interesting to see the result, hopefully spikey will update!

Could be your rack is shot, apparently they were a weak design. Mine would turn left no problem, yet sometimes it would sieze completely turning right! Only a rebuilt rack and pump got me the one finger steering again. Had to replace the altenator too. I get the feeling you are in for a similar experience.

OK http://techinfo.lexus.com/

Thread spammers unite!!!! :whistles:

I thought that too until I did it, but it's real easy. You can get away with just doing step 3. Just find the diagnosis terminal (either in the engine bay or the one in the footwell) and short together with a small loop of single core wire the TE1 and E1 connectors and the codes will start flashing, don't worry about the diagnosis step above, its not absolutely necessary. The codes will keep flashing until you turn the ignition off, so as long as you are not photoepileptic you should be fine! Give it a try!

For true happiness you must stick to your convictions. You asked for the work to be done while the thing was apart, which is perfectly sensible. NO mechanic I know would skimp on such a simple request. My money is on a communication error that meant the job wasn't added to the standard 90K service. Go back in there and calmly, but strongly remind them of how much money you spent with them and that the job is well below the standard requested and paid for. I would remind them that getting the simplest task wrong by overfilling the oil means they have some issues as far as factory procedures and you will not settle for anything less and are willing to persue this issue till its resolved. Anything you can prove in writing or get in writing is heavy weaponary, useful if things get ugly, but they shouldn't if you approach them with a determined stare!!!! Good luck and let us know how you get on. P.S. we are all experimenting on the service life of these cars, hard to predict failure rates accurately since so many factors influence, level of maintenance, climate, useage, drivers foot weight........

That's how I beat the exact same alarm problem on my '92. I have a feeling its the worn key, but just holding it for a second gets around the problem. I have another key but haven't even tried it out as its no problem for me, if it goes off I just try unlocking it again and it always stops. my neighbours love me!

The ECU will not let things activate if it detects that the cam position senors are not working, which is certainly the case with a stripped belt. Get everything aligned as per factory specs and you should be fine. Check the engine mounts too, have heard of them shearing when the cars get a shunt. Good luck!

Its in the throttle body, gets choked up with gunk after a while, go to http://www.lexls.com/tutorials/EFI/throttlebody.html for details.

I had a look at my 92 and there was a cover there, I am doing maintenance next weekend so I will pull it off and have a look.

Its no joke, they last so long you have to put them in your will.... :D

Yup, takes a lot of horsepower to operate the valve gear of most cars (except for rotaries!). Cams should only spin freely if something has sheared off! While you have the belt off its an ideal time to change the water pump and idler pulleys, then you are good for AT LEAST 90K miles. Not to say something else won't need attention though.... Good luck.

Get any fault codes stored on the ECU, they may give you an indication of the problem. 1) Clear the memory by pulling the 20amp efi fuse in the engine bay junction box (check under lid for position) for at least 10 seconds. 2) The 92 ECU has a super sensitive mode that is used for diagnosis, you simplay short together terminals TE2 and E1 in the TDCL diagnosis terminal in the footwell before starting up, go for a drive and it will store the codes from its analysis. 3) with ignition on you connect TE1 to E1 and any error codes will flash out on the check engine light in the combination meter. Count them, ie 2 flashes, pause, 5 flashes is error code 25. Sequence runs from small code numbers up, then repeats. 4) report back here with the codes! its an easy way to keep your lexus dealer honest too!

David, I am very sorry to say if it looks like a duck, walks like a duck and sounds like a duck chances are, its a duck. Unfortunately the transmission will most likely have been damaged by the towing if you are observing the failures in the TCC or lock up.

You can also wipe the error code memory directly by pulling the EFI fuse, look under the cover of the engine bay junction box and you will see it labelled, 20amps. If its disconnected for more than 10 seconds with the ignition off then its wiped, no need to disturb the other settings. The ECU has a super sensitive diagnosis mode that you can activate by connecting TE2 to E1 in the TDCL (diagnosis terminal in the footwell) with the ignition off. Start up and go for a drive then disconnect the wire and connect terminals TE1 to E1 with ignition on and the check light will start to pump out the fault codes. Count them, ie 2 flashes, pause, 5 flashes is error code 25. Sequence runs from small code numbers up, then repeats. Tell us the codes and we will tell you whats wrong!

If they could be removed by water then my guess is that they are dust that has been deposited "electrostatically" onto the moulding at the back of the combination meters, just like powder coating. The magnetic fields around those parts could possibly affect dust deposition, producing the effects you saw. Should not cause any problems as long as the build up is not excessive. I am certain that it is not caused by shorting or tracking as that tends to be a lot blacker! Good spotting.

The best thing to do is get the fault diagnostic code from the onboard computer. I have a '92 and you simply turn on the ignition, then connect a wire with pin terminals between the TE1 and E1 terminals inside the diagnostic connector or TDCL. This is found near the hood release (TDCL stands for Toyota Diagnostic Computer Link at a guess and each terminal is labelled under the lid) and the fault code will be displayed as a series of flashes on the "check" engine light. It flashes two numbers, i.e. two flashes pause 5 flashes is code 25. Sequence starts at low numbers and works upwards then repeats. If someone could confirm that the later models retained this functionality then we will help you once you report back the code (literally takes 3 minutes to get them!) Good luck.