Greavett

Just though I would share this with you as some of you may have similar problems, mainly with the 3UZ-FE engine. I started to experience an engine misfire on startup which lasted of all of 1-2 seconds. It always cleared and ran perfectly after wards. I could smell excessive fuel from the exhaust after intial start, but again that cleared after start up. Problem seemed to be less pronounced when cold, but mainly because of the nature of cold start need for richer mixture. I had my suspicions that the fuel injectors may be the trouble, or maybe the ignition coils or even the engine temp sender for the e.c.u. I ran all the tests on the sensors, including cam and crank sensor checks hot and cold. Still no obvious anomolies! Now, usually with fuel injected cars they run a return to tank line, which after the regulator usually terminates back in the fuel tank. This is really helpful, it enables you to manually restrict return line flow which in turn increases fuel line pressure. Usually problems with injectors are related to poor discharge patterns, normally caused by a partial blockage, or weak electrical coils within the injector itself. Now on conventional cars if you have a misfire and you suspect injectors, you can restrict the return line with a clamp. This usually improves the spray pattern for the faulty injector and will usually remove the miss for as long as the clamp is installed. Running with the clamp is not desirable due to the extra load it would put on the fuel pump (raised pressure), but your testing has highlighted that it's likely to be an injector. So a clean will normally fix them..........usually!! The LS430 does not have a return to tank line, and so it's almost impossible to restrict the return line to overcome possible spray pattern issues which will give the miss. I removed the spark plugs after the car had been sitting for a while and inspected which plug was discoloured differently to the others. I found number 8 plug was glazed and swapped it out with another. I let it run for another week or so to do a fair test, then removed them again for inspection. Found the swapped out plug was clean, but the new plug in the cylinder that had given me the glazed plug was now also glazed. Ok, so I had found the cylinder which was responsible for the miss, could be one of three things from now, mechanical problem, fuel problem, or ignition problem. Starting with the easiest first I changed out a coil pack for a neighboring cylinder and left the car run another week. Removed and inspected plugs again and still the same results. Same cylinder with glazed plug. Next thing to check was the mechanicals, I discarded this check mainly because the car runs well after start up, there is no miss from the exhaust and no lack of power. Finally I was totally convinced it was the injectors. I got a set of serviced units from the states and installed them. The first two start ups were perfect, and I was pleased with my diagnosis. Or at least I thought I was!! The next day the fault had returned, not much worse, probably the same, but still there. So I ran all the checks again, and came back to the same conclusion. Injectors. I've had it one time before where the older model 1UZ-FE had the same sort of issue, only found the injector failing when using and oscilliscope. It showed a lazy coil pattern, easily identified on a scope with a second pulse after the intial activation. The other injectors did not display the same pattern. So again I ordered injectors and installed them. This time the fix was instant and long lasting. It's been running good ever since. I don't beiieve that the original set were not cleaned satisfactorily, just more that the activation coils may have already become weak. I read a few posts on LS430 Misfires, but none of them had any answers or fixes for the concern. If your V8 lexus is missing briefly on startup, it might be worth a look at your injectors. To reduce the likelyhood of failures due to contamination of the fuel circuit, I changed the in-tank fuel filter under the rear seat, (mostly forgotten about). I only paid around the $35 per injector from the states, all genuine Denso and all brand new, not reconditioned. I will always go new from now on. I also want to mention that the front four and rear four injectors are a different part number however.....the injectors are exactly the same. The difference in the part number is the little jacket that the rear ones wear to reduce heat soak. These jackets are removable and can easily be fitted to the new injectors. The reason I added this is because the front four injectors use a fairly common Denso injector, and you are going to find them easier for cheaper than the rears. Any way, I just thought I would share this with the forum, hard problem to find because of the time span of which it actually occured. With a return fuel line, the diagnostic would have been far quicker. Hope this helps out other LS430 owners Simon

No problems! Thanks Simon

Hey Subby, There will be some hidden bolts/screws behind the panels, and if you can't see any at all after an extensive look, you may find that they are retained by wedge type fastners common to Toyota and Lexus. The lower panel near your knees is generally the easiest panel to remove in the car as it's used for main access to the ignition harness etc. I'm sorry I can't be more specific but maybe some IS owners can shed some more light on it for you. Thanks Simon

Hey Ric, From memory, the cover is screwed in from behind the panel so don't pry it too hard. You will have to remove the ignition key surround (just pulls away) remove the coin tray, think there is a bolt behind it, another behind the handbrake lever, just pull the lever to gain access. Then I believe there are two more bolts at either lower end of the panel. Gently lift the panel out and down. There will probably not be a fan on your model as there was none on my 95. Instead it uses a draft feed from the heater box to draw the air over the resistor. Just pull of the rubber hose for that, disconnect the wiring and give it a bit of a gentle clean, re-fit in the reverse order. The fuel flap and bonnet release cables can be left on the panel, and just work the panel to the postion you need to get at the sensor. Hope this helps Simon

Agree Bacchus, Screen anything from 250-500, Creaky suspension can prob be fixed with a bit of lube spray, (dry bushes), bonnet struts you can get re-gassed mileage brings it in at approx 17000kms per year, which is still below average most people travel a year (20,000) approx. CD stacker you will prob find in a U.S wrecker, couple hundred bucks! Timing belt parts you can get from Repco, but get a timing belt kit, comes with tensioner and pulleys. I would also be doing the waterpump whilst your there at that sort of mileage. Hope this helps Simon

Hi People, Was driving today in the heat of a Queensland summer, climate control happily purring away keeping the sweat from beading on my forehead. I thought of an interesting little thing you can all do for your A/C systems to make them a little more reactive to your temperature setting in side the cabin. It is usually forgotten and once you do this little job you will find your Climate Control will return to being a little more effecient in the co-efficiency between your set temperature and what the system actually believes is the temperature inside the cabin. Usually your modern A/C system uses a couple of sensors to detect the temperature within the cabin, the sun light hitting the car and the internal temperature of the A/C system itself. I've been in numerous cars that when the A/C is set to 25'c it's no where near enough to keep the car to a nice temperature, you end up running the A/C at 18-20'c just to get the temp you desire. Amongst a failing A/C system with low gas or other problems there is a simple job which every one can do to make your A/C more reactive to interior temperature vs selected temperature. When you select say 25'c the Ecu for the A/C will determine the amount of sunshine (solar sensor) vs Temperature demand (you selecting the temp you want) and the current temp output from the evaporator. Please don't quote me on the sensors this is just a summary of a basic system to keep it simple. However, over time, the one sensor which collects dust like no other is the in cabin temp sensor. It collects dust because it has a handy little fan behind it, to draw in cabin air over the sensor (resistor-i-think, similar to MAF sensor). The effect of this collective build up of dust and fur is that when you dial in your A/C to 25'c, your system will try to read the temp of the cabin air though the crusty dust which surrounds the sensor. Now those of you that have had Air Flow sensor problems due to dirt/oil on the resistor will understand that it does definitely effect the acuracy of the sensor. Some of you through cleaning may have already come across the little sucker behind the dash, most I would expect would not know what it is. With out pictures I will endevour to explain how to find the sensor on your A/C so that you can remove it, clean the fan and sensor so that your A/C system will get it's Climate Control nervous system back!! They are usually located on the drivers side dash panel. Normally around the steering column area below the binnacle (Speedo Cluster). They are usually inserted behind a small removable panel, which looks similar to an empty switch panel, except that it will have a number of horizontal vent holes. In size, approximately 5 cent piece, but the panel in which it sits can be quite a bit larger. Gently prize the panel off, being careful not to damage either the wiring harness or the sensor/fan assembly. Behind the vent I will almost put money on that all of you will find some level of filthyness!!! Very carefully using cotton wool, or an ear bud, and some very gently electric cleaner such as Iso butamol (i think that's what its called) Dick Smiths sell it for PC guys, clean the surface of the sensor and the fan. Turn on your igntion and check that with the A/C on and running the fan does in fact work, and if it does put it back in your dash. You will notice that your A/C Climate control is able to respond quicker to your temp commands and will maintain the correct level of cooling better without the sometimes large variation between cold and icy cold. Give it a try.......I bet you all find fluff!!!! Let me know how you go!? Thanks for reading Simon :)

Some of the older holden V8's can run good all day long and only give bad missing running issues when given the beans at the top of the rev range. Usually connected to worn cam lobes, but it's doubtful you would have the same wear issue, just out of timing. Seen belts jump on a couple of cars now, doesn't happen all that often....but it does happen 100% Simon

Plenty of mods can be done, a famous line in a movie I recall is "Speed is a question of money.....how fast do you wanna go?" There are definatelty bolt on Supercharger kits available, and I've even seen the twin turbo kits, not to mention cams and intake systems upgraded injectors, fuel pump, engine mangement etc. Budget is the only thing limiting the LS400 Simon

This is a typical high end rev issue which could most definately be related to cam timing. It's possible it has jumped a tooth, but you only have one way of finding out........have a look! Poor old LS getting it's neck rung like that!! ha ha! Go the Japanese V8 Simon

Hello, Firstly we have to determine if the system is still operating when it stops cooling. So need to run the car until the A/C stops working, then we need to look under the bonnet for the A/C compressor (usually hard to see). Need to see if the end of the pulley is rotating, not the bit the belt drives but the magnetic clutch. If we can determine that it is still running but the car is A/C is not cold it could be a Thermistor or TX valve causing the problem. If it is not running, then we would have to find out what stops it running, I.e electrical, control, or other problems, Hope this helps Simon

Hey Mate, You might have already fixed your A/C but the best way is with the dye and ultraviolet light. The best thing you can do though is take it to a specialist. They will have all the gear and find the leak efficiently. Your lights flickering on the A/C panel may just be down to a loose connector on the back of the panel, could even be poor terminal tension in one of the plugs. Hope this helps Simon

Is there really any question of which you would choose. I mean your on a lexus forum!!!!!!! Lets put it simply, The 460 may chew a bit more fuel, but it's a luxury vehicle. The Japanese choose Toyota/Lexus almost like religion. They like having the best of the best. Not sure about the problems that 460 may have as it gets older, but i'm sure there will probably be very few. The only thing I would be concerned with is maybe the market value. But that all depends on how much you pay for it now. Unfortuanetly Lexus suffer from a bit of a bad resale value with in a few years of purchase. But that means that the less fortunate (income wise) can enjoy luxury motoring....not to mention Japanese luxury motoring at a good price. Lexus every day of the week my friend in my opinion. What makes you put the liberty up as a compare. Surely they are a world apart. Simon

I believe it will.....one day. As for shipping a man to the moon. I'm not actually sure that really ever happened. I mean....1969, leave the earth, orbit around the moon, land with a space lander, walk around a bit, get back in, launch then re-dock then re-enter earths atmosphere, land in the ocean and all is well!! In 1969. You know the trouble we have with complicated technology now, so can you imagine that really ever happening back then!!!??????? Conspiracy theorist I think may just have this one in the bag!!! And of all the people to recently take a picture of a moon landing spot.....guess who......NASA!!!!!!! Hm, questionable in my opinion. Petrol yes.....moon no!! :D

That's the sort of blunder I would expect from Land Rover not lexus. I would have thought it near impossible for heater units to be installed in the wrong vehicle...thinking along the lines of production techniques...particularly production line assembly. But from my experience especially with the Range Rover HEVAC (heating and ventillation & A/C)which was always having issues, it sounds to me like the blend door which seperates the hot from the cold have stopped working. The blend doors are what give you hot on one side and cold on another. there will be multiple doors and flaps most likely controlled by electric motors. It's most probably a door motor or control for that motor in terms of a control unit (ECU). I like you would be a little dissapointed if they really have fitted the wrong heater/cooler assembly!!! Thanks simon

Would say most of your light problems stem from poor idle conditions, Sort idle out and the rest should come good my friend! But it could also be your alternator on it's way out! Your speedo problem would most probably be in your binacle. (Guage cluster) You may find with more use it gets better, other wise get your self a good second hand one. I take it that it's a new purchase? Simon