20 Most Recent 1990 Lexus LS 400 - Page 7 Questions & Answers

You no longer need to time engines like you use to in the old days. The computer advances and retards the timing depending on the information the computer is receiving from the sensors. Years ago you would adjust the distributor by twisting it while reading the degrees on the crankshaft sensor, with a timing light, and setting it to a desired spec. This is no longer necessary. Thanks and good luck :O)

1990 Lexus LS... | Answered on Feb 17, 2011

possible fuel leak. lay under the vehicle and trace the fuel lines from the gas tank to the engine. if you find any wet spot on them that you know is gas replace them. especially on mpi vehicles, they need pressure to operate

1990 Lexus LS... | Answered on Feb 12, 2011

there is a fuse box under the driver side dash near the pedals. you must first remove the protective cover from the outside and then you can see the fuse control panel.


1990 Lexus LS... | Answered on Feb 05, 2011

i think you need to reissue your question. it doesnt really make sense what u are saying

1990 Lexus LS... | Answered on Jan 23, 2011

Although the LS 400 is a great car, the engineering could have been a little more "consumer oriented," when it comes to repairs.
I'm sorry to be the bearer of bad news, but the starter is in the middle of the engine, underneath the intake manifold. This means you must remove the negative battery cable, empty the coolant, remove the air intake assembly, the throttle body, all of the vacuum lines, hoses etc. and then the intake manifold. The starter is located under the intake.
If you are a "back yard" mechanic, you can do this yourself. It's not very dificult, just extremely tedious. It also doesn't require any special tools, just the basics, such as a metric ratchet set and open end wrenches. It would take a pro about 5 hours.
Good Luck!

1990 Lexus LS... | Answered on Jan 19, 2011

the bearings in the water pump are going bad, it should be replaced asap

1990 Lexus LS... | Answered on Jan 16, 2011

replace the temputer sensor and should be diy friendly

1990 Lexus LS... | Answered on Jan 14, 2011

it is not nessesary to drain it, if you have a way to get the tank back up when you are done, it makes it a bit harder to work with just be careful with your body stadic, empty or full, stadic will cause fuel to ignite ground yourself to prevent this

1990 Lexus LS... | Answered on Dec 25, 2010

sometimes your alternator works when it wants to its a sign of it starting to go bad how often does your battery go dead how long does it take before car will not start up make sure battery terminals are clean and tight have it tested again there is no way to reset battery do you have a light in your trunk who told you something was staying on killing your battery

1990 Lexus LS... | Answered on Dec 24, 2010


The fuel regulator is located behind the back seat. There is a 9" access port in the center of the fuel tank behind the back seat. located in the center of the open port you will see a fuel hose with some hose clamps....the 3 semicircular bolts that line the bottom of the portal anchor the bracket that holds the fuel regulator mounted deeper in the fuel tank.

Take care and good luck

1990 Lexus LS... | Answered on Dec 02, 2010

How old is the exhaust converter,could be plugged
Gas filter clogged?

1990 Lexus LS... | Answered on Nov 24, 2010

This problem is caused by a dirty idle speed control valve and throttle valve, do the following procedure i have used for many years to help improve this condition.

To correct this problem I want you to get a can of intake cleaner (ABOUT $5.00) from any local auto parts store like NAPA or Carquest, do not use carburetor spray, intake cleaner only or u will damage the Teflon coating inside the throttle valve and air bypass valve, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

1990 Lexus LS... | Answered on Nov 23, 2010

make sure the spark timing is right. check the timing mark is correct.

1990 Lexus LS... | Answered on Nov 19, 2010

Overtime an ignition switch wears out. Sometimes to where you cannot turn they key anymore so you should have your ignition switch replaced. You will have another key on your key-chain but keep your old key to unlock your doors and truck.

1990 Lexus LS... | Answered on Nov 16, 2010

More often than not, the starter will be located on the under side of the motor on the same side as the battery. trace the red or positive battery cable and it will lead you right to it. It will be short approx. 8 inches long and about the same diameter as a Mayonnaise jar.

1990 Lexus LS... | Answered on Nov 11, 2010

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