wwest

Check the brake pedal switch that turns on the brake lights, it may be adjusted just a little too critically, "hair-trigger" one might say. Also ALL your rear brake lights must be functional, including high mounted one, or the cruise control will sometime be intermittent. You cannot use LL, Long Life, type bulbs nor LEDs in those sockets without compromising the cruise control's "brake-on" monitoring cutoff circuit.

Yes, and that's exactly why most most modern day EFI system's will and do enrich the mixture. You are correct, retarding the timing will help... provided the knock/ping is due to timing being too far advanced. But putting a too low grade fuel in a high compression engine is more likely to result in dieseling, is it not? Knock/ping, !Removed! the timing....Oops, that didn't help, knock/ping must have been due to dieseling..... I suppose the systems are now smart enough that if they detect knock/ping co-incident with, or just after ignition spark.... Shouldn't have dieseling with a fuel injected engine (unless one of the injectors is leaking) since the ECU is able, via the injectors, to shut off fuel flow completely - so in a properly running engine there won't be any extra fuel to sustain dieseling. Even if the ECU enriched the mixture, it's ability is severely limited because of emissions control - particularly since this engine was designed to meet California Low Emission Vehicle standards. This from the Lexus.com FAQ: "Use of lower grade fuel will typically cause some degree of improper combustion, which results in engine knock. When the engine management system detects knock, such as with the use of lower grade fuel, the ignition timing will be retarded. While retarding ignition timing helps to minimize knock, it also reduces available performance and fuel economy....Regular grade fuel may be your best option, if, based on your driving conditions and driving style, you don't notice a difference in performance or economy between regular and premium." I wasn't discussing throttle closed "run-after" dieseling, that went away way back in the stone ages (carburation) with the use of idle solenoids to completely close the throttle. Nor at idle or normal cruise which is when the mixture is controlled for EXACTING emissions level by the oxygen sensor signal. At the same time the MAF sensor signal is being calibrated using the oxygen sensor as reference. When you put the engine under load, acceleration, uphill, the A/F mixture is enriched, >12:1, beyond the sensing range of the oxygen sensor. And then's when you're most likely to get dieseling due to too low fuel octane for the HIGH compression ratio which is correctable via EFI fuel enrichment.

Spokane is only 275 miles away and it's a beautiful day for a drive...

"no amount of retarded timing will help..." Yes, and that's exactly why most most modern day EFI system's will and do enrich the mixture. You are correct, retarding the timing will help... provided the knock/ping is due to timing being too far advanced. But putting a too low grade fuel in a high compression engine is more likely to result in dieseling, is it not? Chicken or egg...? Knock/ping, !Removed! the timing....Oops, that didn't help, knock/ping must have been due to dieseling..... I suppose the systems are now smart enough that if they detect knock/ping co-incident with, or just after ignition spark....

If the RX transmission is so bad, why don't Toyota Highlander owners have the same complaint? It's the SAME engine and drivetrain. Search the Highlander forums and you'll find few, if any, transmission complaints. Its already been posted that Consumers Reports shows no transmission issues either. If anyone were to highlight a problem with the RX unit it would be CR. The only other comment is that if, and when, transmission service is performed you MUST use the Toyota Type IV transmission fluid. I know one thing. I just bought a 2001 RX 300 with 58K. I checked CR and their glowing review was a key ingredient to my purchase. After seeing these post I am sorry for going with the Lexus. I fully expected to get 250K from this luxary vehicle. kp Well dont get too upset, I've mentioned before (probaby in theis actual very long thread) its the 99/00's that have been reporting higher than normal (my opinion) failure rates. The 01-03 had changes made to the transaxle that seem to have minimized the problem. Yes , of course there have been a few failures of 01-03's but then again there are always going to be a few failures of anything produced en-masse especially complex machinery. What I need to see before I say problem is a repeated pattern of the same part failing. Iv'e seen it on this and other forums with the 99 and almost enough with the 00 but very few with the 01-03's and not enough to say the design flaw wasn't corrected. At this point in time there should be plenty enough miles on 01-03 vehicles to have uncoverd an endemic flaw. "The 01-03 had changes made to the transaxle....." Yes, and I quite firmly believe the primary change was to go to a higher volume gear type ATF oil pump. A higher volume pump would certainly help solve the earlier problem due to not having enough ATF pressure with the engine ar idle to support two gear shifts, lift-throttle upshift following quickly by a need to accelerate. Then the law of unintended consequences came into play. At high engine RPM during cruise that oil pump pumped, pressurized, a LOT of excess ATF that simply got bypassed back into the sump to become WASTE energy dissapated as HEAT. So even with all being equipped with the towing package the '01-03 models are suject to ATF overheating by about 40,000 miles. Thank God for DBW for the RX330...

Look at the statement in bold print. This is significant because the gasoline we buy here in CA is labeled as having an octane rating of R+M/2. To me, this means that Lexus requires 87+91/2 = 89, which is an average of RON and MON. If I am correct, this is the minimum octane of gas that is recommended. During Winter months, I have successfully used regular RON +MON average of 87 and have not experienced any knocking whatsoever. However it is my experience that this may be insufficient during the Summer months. If anyone believes that they are buying pure Research Octane-rated fuel, please chime in and let us know, but I did check the pumps here and saw that our octane numbers are an average. Thoughts? For normal non-defective gasoline modern day EFI engines there are two times, "phases" in the 4-cycles wherein octane rating of the fuel will be important. The first of these is actually during the late phase of the compression cycle where a too low octane rating may result in engine knock/ping due pre-ignition/dieseling. The second is due to engine loading. Knock/ping due to "lugging" of the engine during the combustion cycle's downward stroke of the piston results from the piston not being able to move downward as fast or as quickly as the flamefront, EXPLOSION, is expanding. With high octane fuels the progression of the flamefront is more "evenly" spread over the period of the downward travel of the piston. Whereas a lower octane fuel's flamefront will not be as "linear", detonation will in a more explosive, more defined PEAK, fashion. So fueling a modern day high compression engine with an automatic transmission with a low octane will have no detrimental effects at all. The engine control ECU will simply enrich the mixture to prevent dieseling and the transmission will be downshifting to prevent any knock/ping from lugging. But. Anyone know of any advantages or detriments to fueling a modern day EFI (forget carburation) engine built for low octane fuel with a higher octane than suggested?

I wonder how much the compression ratio changes if I use a "cold" running spark plug vs a "HOT" one....??

Those gauges and indicator icon bulbs are driven by the engine ECU so it's more likely an intermittent connection. Only one gauge acting up = most likely the guage itself. Two guages acting up (simultaneously?) = common signal source. I assume the engine is operating satisfactorily so nothing serious is wrong with the engine ECU.

Compressor is automatically cycled off if: 1. High side pressure is high enough indicating sufficient liquid "store". 2. Low side pressure is too low indicating lack of sufficient refrigerant charge. 3. Evaporator surface temperature has declined to or below ~34F 4. Engine coolant temperature is approaching criticality. 5. WOT 6. OAT is below freezing. What you describe may very well be TOTALLY normal operation. So as to not discomfort the passengers the Lexus NEVER blows very COLD airflow except at 65F setting, maximum cooling, and manually set low blower speed. Once the cabin atmosphere is cooled to near, within a few degrees, of your setpoint the remix/reheat cycle is set to provide only moderately cool "maintenance" low volume outlet airflow. You can quite radically inprove the A/C efficiency, and substantially improve FE, during the summer months by disabling the reheat capability. Remove the push/pull remix/reheat door servomotor link cable from the water flow control valve at the top center of the firewall in the engine compartment and twist-tie it, the valve, into the fully closed position. No HOT water flow, no WASTEFUL reheat capability....

"Just a guess, but.....Totally open, WIDE open, expansion/metering valve. But that just could be due to RAPID use/cooling with such low refrigernat fill. Compressor is disabled/protected if refrigerant pressure is too low. You are adding refrigernat via the low side...??

If an engine is designed from the get-go to take advantage of the higher octane of premium fuels it almost always has a higher compression ratio as the primary difference between it and engines that are designed to use regular grade fuels. If you fuel it with a low octane fuel the engine ECU will simply enrich the mixture in order to keep the high compression engine operating optimatelycorrectly. On the other hand if the engine is designed for low grade fuel to begin with what can be done to take advantage of preminum fuels? Reduce, lean out, the A/F mixture ratio..?? It seems to me that absent that higher compression ratio using premium fuels can have no advantage.

The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant. Is there a certain high and low preasure reading? I have 45 psi on the low and 170 psi on the high at about 75 deg ambient temp. Good readings insofar as I know. Why are we pursuing this line? Because your compressor runs continuously? That may be somewhat normal depending on circumstances.

#1 clue...at max cooling or max heating ALL sensor signals are ignored and the pertinent servomotors are driven BLINDLY into the appropriate position. SO. You have a input signal sensor (not likely to be a servomotor positional feedback sensor since it lags but "follows" the temperature setpoint) somewhere that is intermittent. I would check/replace the cabin temperature sensor first. It's behind "window" in the dash panel just above the drivers right knee.

"air mix......" Don't know your MY but for early LSes check the coolant flow valve to the heater core to see if its seized. Its mounted at the top center of the firewall in the engine compartment and and should move from fully closed to fully open as you move the control back and forth from 65F to 85F, full heat to/from maximum cold. If it does not move then remove the push pull cable from the valve and see if it, the cable end, then will move. If it does then the water flow valve is stuck, a fairly common failure. With the push/pull cable off you should be able to grip the water flow valve control "arm" and fairly easily move it full travel, about 90 degrees. "air inlet...." By removing the dash mounted glove box entirely you should be able to observe the air inlet door/damper move from fresh airflow to recirculate as you switch between those modes. None of these have anything to do with compressor failure or not. I don't have my shop manuals here at the office but it may be the these two servomotors share a common fuse and a stuck water flow valve caused the fuse to blow.

I think I have read somewhere that what you describe is being done intentionally so as to give you the expected "feel" of a normal car with an automatic transmission. On the other hand it may be part of the current ongoing effort by the industry at large to remove some of the hazards of FWD. Engine "drag", or engine compression braking on the front wheels can most definitely interfere with the proper operation of your anti-lock braking system. The "rise" in drive torque to the front wheels during braking may very well be in an effort to protect you from loss of directional control should the roadbed happen to be slippery.

In H&H, HOT & HUMID, Memphis last week with my brother's 91 LS400 the only way I was able to get the compressor clutch to cycle off, and/or the electric radiator cooling fans to cycle on, was to first cool down the interior atmosphere in recirculate mode and then reduce the blower speed to minimum to reduce the rate at which the refrigernat was being "burned off" via otherwise "warm" airflow through the evaporator. Temperature was in the ninties so "fresh" mode meant 90F incoming airflow and RAPID refrigerant evaporation. It took 48 ounces of R-134a to get to that point. Other than the compressor constantly engaged if the system is cooling well then I'm not sure I would worry overly much.

The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant.

You definitely did it the correct way--utilizing new projector beams that have the proper pattern to "contain" HID output. Unfortunately, there is no projector retrofit available for 1gen LS400, and we are stuck with the awful glass lens that actually produces the "pattern". These make for an awful glare problem when simply replacing the 9004 bulb with an HID kit. The Hi/Low kits that move the filiment are less than ideal for 1gen LS400 applications, as again, the pattern on the glass headlight housing of the LS400 does not provide a proper pattern for the now-moved Hi-beam light source. Since the fog lights are virtually useless anyway I have often thought about using their housing as a start. Buy a "take-off/out" (presumably from a totalled out wreck) bi-xenon projector set and retrofit them into the LS400 fog light assembly.

With the A/C "on", enabled, there are only a few things that will result in the compressor clutch being disengaged. 1. Refrigerant pressure too low...generally meaning low on refrigerant. 2. Refrigerant pressure high.....normal occurrance. 3. Evaporator temperature too close to freezing. 4. OAT below about 35F 5. WOT. 6. Engine coolant temperature too high. Running continuously might mean the system is heavily loaded, liquid refrigerant is being exhausted as fast as it can be compressed/pumped, HOT day, bright sunshine, 4+ passengers, black exterior/interior, open windows, etc. Or it might also mean the refrigernat level is marginal. WOT, Wide Open Throttle, kill the A/C all power to the roadbed.

I just upgraded my 2001 Mustang Convertible to projection headlights and HID. The new headlight assemblies where $150 on Ebay including shipping and the H3 HID kit w/Hella Ballasts was $100 including shipping. Stunningly impressive even with the SHARP cutoff of the high side HID beam pattern provided by the projector lens and apperture. The are several types of HID hi/lo kits available, most, and the best, move the HID light source electromechanically from one position to the other for hi/lo operation.

Strange you should ask that question at this particular moment in time... I just returned from Memphis where the A/C in my brother's 91 LS400 had suddenly stopped working. It didn't take long to discover that there was NO refrigerant in the system. 16 year old car, 150,000+ miles and SUDDENLY the refrigerant (assume freon) has gone missing. Just after a visit to GoodYear for an oil change....... I looked the system over for leaks and the only thing I found was that the top of the EPR valve was oily and dirty from dust sticking to the oil. removed the cruise control to have a better look and low and behold there lays a red straw very much like attached to a can of WD-40. So I called around to get prices/quotes for checking the system and converting to R-134a. First call was to Lexus of Memphis who told me that on a car that old they would simply start by replacing all of the major components since installing only the "failed" one would undoubtedly overstress other components resulting in them also failig. "Don't call me, I'll call you" was my response. Second quote, yellow pages, was $450. Third quote, Hacks Cross area, was for $150. I paid $125 in Bellevue WA last year to have my LS converted. Converted the system to R-134a (48 ounces??) with no repairs whatsoever and a week later it is still holding the charge. I understand GoodYear pays their mechanics/techicians 30% of any "upselling" they do, but.... You can buy a kit and enough R-134a for ~$50. Legally you should have a shop pump down the system, remove all the freon for recycling, before installing R-134a and the system will need a few ounces of oil and only the A/C shop can do that for you.

Yes, absolutely, keep driving. Where I live the 92 TC is only useful as an indicator of slippery roadbed conditions that otherwise might be un-noticeable, in LA probably totally useless.

With the A/C "on", enabled, there are only a few things that will result in the compressor clutch being disengaged. 1. Refrigerant pressure too low...generally meaning low on refrigerant. 2. Refrigerant pressure high.....normal occurrance. 3. Evaporator temperature too close to freezing. 4. OAT below about 35F 5. WOT. 6. Engine coolant temperature too high. Running continuously might mean the system is heavily loaded, liquid refrigerant is being exhausted as fast as it can be compressed/pumped, HOT day, bright sunshine, 4+ passengers, black exterior/interior, open windows, etc. Or it might also mean the refrigernat level is marginal.

The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level.

BUY IT, NOW, QUICKLY...!!!