1998 Lexus LS 400 - Page 7 - Answered Questions & Fixed issues

Well I would first ask why you would want them on. The computer grounds the fan relay when the fans are needed.They don't run until the ac is on or the engine reaches 220 degrees.Sometimes smoke in the radiator is a sign of a leaking head gasket.

The code for the sensor is the giveaway.The computer does not know how much fuel to give the injectors without that sensor working. The computer uses a factory set default reading.Assuming the cooling system is full of fluid, you should be able to test the circuit and the sensor with a meter and a scanner. The sensor is a resistance variable that takes a 5 volt reference from the computer and changes it depending on the resistance in the sensor.The sensor should read different resistance at different engine temps, and the harness should carry the voltage back to the computer. The scanner should show the sensor reading as the engine warms up.

HelloThe Engine and Automatic Transmission (not applicable to manual transmissions) in this vehicles drive train are fully electronically controlled by a computer called the PCM and TCM (Power Train Control Module, Transmission Control Module). When a problem like this or other drive-ability related problems occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM. Also always check fuel pressure for correct spec for your make and engine type.

Then a problem is occurring in the system, have the dealer scan it and see what is keeping it from starting. It may not be the alarm system, other problems may be occurring.

The voltage regulator for the alternator is located inside the rear housing of the alternator. It can only be accessed by removing the alternator and dismantling it. If the regulator is faulty it is repair by replacement usually by swapping for an exchange unit from an auto electrician. If the alternator is not charging it may just be a case of the brushes inside the alternator being worn out and requiring replacement.It will still be required to remove and dismantle to carry out their replacement.

I'm pretty sure only Ford products have a safety switch for the fuel pump.

idle air control valve is shot, replace it

remove the door panel the plastic clip attached to the window has broken away from the regulator arm. you can replace the regulator easily at that point or you can cut a 2x4 to fit and do not forget to unplug the regulator motor. jam the wood between the window and the bottom of the inner door frame.

are you sure you didn't blow a head gasket?is it whit smoke?

Need to check next time it quits,pull a wire and see if it has spark,I suspect it is a ignition problem,not fuel.

More often than not this is caused by a large vacuum leak on the engine, the surge up and down is the computer trying to slow the idle. Use a bottle of propane gas and a torch adapter with a rubber hose on it, spray the gas around the top of the top of the engine and alos around any vacuum hoses from the engine, if you hit a vacuum leak the engine will sound much different, repair as needed.

idle control motor its on the inlet manifold and either needs renewing or a good clean

First, make sure your battery is fully charged.Next, check your plus and minus connections on your battery posts. Don't just check them, clean the clamps on the inside and the posts. They make a tool that is a battery post wire brush tool for under $6 bucks, get one so you can clean them well. This may help the issue. Once they are clean and it still is slow starting, my conclusion would be you may have a bad starter. The slow start means you typically have a dead spot on the starter armature which you cannot do anything to fix, replace it. .Their is only other reason it could be slow to start and that is if you had a compression issue, and your car actually runs, so that is not it.

Hi.

There is no document showing a single procedure for vacuum hoses, fuel hoses and wiring in the engine. The procedures are illustrated in the single document of ENGINE MECHANICAL, SFI, IGNITION, EMISSION CONTROL, COOLING, CHARGING and AC sections of service manual (e.g. see individually vacuum, fuel system, EGR, IAC, cooling system etc.) . The whole diagrams and the single procedures to reassemble the hoses and wiring in the engine compartment are in the service manual. The service manual has been uploaded here. Click on the rapidshare download page and in the page use the Green button to download for free to your computer. Any other option will ask you to pay extra to download the file (sorry but the free file repository service works in this way).

Regards.

Ginko

Try first to jump start the car with another idling car. If you get the car running it is likely a power supply issue. To test if it is the battery or the alternator, remove the jumper cable and then the negative terminal. If the car dies after awhile then you may have a weak alternator or the lines from the alternator may be bad. If it runs it is the battery that may be weak.

If jump starting the car does not help then it may be an electrical issue. It may be a bad starter relay or the starter may be going bad. Heat affects the starter and the wiring. Inspect also the wiring for loose connections or exposed conductors.

u can get in the car correct? If not you need a locksmith or the dealer, but if you can get in. I found a great method to get the trunk popped if your car is still open and the trunk lock is activated. Drop the under dash. 2 screws under the gas tank/ hood/ trunk release cluster. The panel left of the steering wheel pops off with safe prying. 1 more screw and another tab. Then you have access to the backside of the trunk release. Unplug the relay behind the switch ( Should be the blue/black wires) Use a paper clip to touch both the positive and negative points of the relay. Pop and wallah the trunk should open. Worst case situation you can remove the rear seat or subwoofer to gain acces to the trunk. pop the subwoofer out and get a coat hanger or remove the seat to get the keys. If you type in( how to remove the back seat of my 96 lexus ls 400) in your google search bar there are several posts on how to do this.

I don't think I've ever worked on one of those... I can give you general instructions, though. First of all, you probably have some plastic covers on your engine - remove them first. Then remove your plug wires. NOTE: it is a good idea to mark them first; normally they are in specific lengths and will only fit back on one way but you do not want to mix these up! Find out what the pug gap is for your engine (most cars have the plug gap included in the info on the engine decal stuck to the underside of the hood or elsewhere in the engine compartment) and gap your plugs. If you cannot get them exact, a bit smaller is better than a bit bigger - gaps grow over the course of use from all the heat. Taking care NOT to get any dirt in your cylinders, (best blow with compressed air around the plugs first) pull your old ones using a spark plug socket (regular deep sockets lack the rubber boot that protects the ceramic). Have a look for any abnormal conditions when they come out: are they black? wet? white? all different? these conditions will tell you if there is something else going on in your engine. Check the box of new plugs for torque: usually the package will say something like 18 ft-lbs or quarter turn past snug or something like that. This is very important - tighten just a hair too much, you pull threads out of your head - tighten not enough and you risk having them be blown out. IF package doesn't say: is there a crush washer? If so, go finger-tight then 1/4 turn; if not, go finger-tight then 1/16th turn. If you can't get your fingers in there to turn the plugs in, use a piece of rubber hose stuck on the tip of the plug and spin the hose.

DRAIN COOLANT SYSTEM.DISCONNECT THE RADIATOR INLET HOSE FROM INLET PIPE. REMOVE THE TIMING BELT FROM THE WATER PUMP PULLEY. REMOVE THE RIGHT SIDE IGNITION COIL.REMOVE THE WATER INLET HOUSING AND THERMOSTAT.REMOVE THE MOUNTING BOLTS AND STUDS. LIFT OUT THE WATER PUMP BY CAREFULLY PRYING BETWEEN THE PUMP AND THE CYLINDER HEAD. REMOVE ALL THE OLD PACKING AND CLEAN THE MOUNTING SURFACES. INSTALL NEW SEAL PACKING TO THE WATER PUMP GROOVE AND A NEW O - RING TO THE WATER BYPASS PIPE.INSTALL THE TIMING BELT AND CONNECT THE INLET HOSE TO THE INLET PIPE.THEN REFILL THE COOLING SYSTEM. RUN THE ENGINE CHECK FOR LEAKS.

levers are usually connected to cables. can you reach under the car to the cable and pull it manually?

The two are unrelated. First the no power is the catalytic converter, it is clogged up. Second is the purge solenoid is not working. The solenoid could be bad or the wiring. Check engine light on?