Question about 1990 Lexus LS 400
Could have faulty spark plugs and wires,incorrect gapped spark plugs, clogged fuel injectors,clogged fuel filter,plugged air filter,could have low transmission fluid level or need transmission fluid changed, checked for restricted exhaust system, plugged muffler or catalytic converter will take away engine power.check the engine compression worn pistons rings and valves will cause power lost.you can hook vacuum gauge to intake manifold vacuum port,good steady engine vacuum will be 17 - 25 hgs. if engine vacuum gauge needle drops to 5 hgs more likely you have restricted exhaust system, either muffler plugged or catalytic converter could be plugged.
Posted on Feb 06, 2012
The first thing to have checked is the fuel pressure, low pressure kills the power.
Posted on Feb 06, 2012
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Posted on Jan 02, 2017
Try rotating the ignition switch slightly after you turn it to on and see if the lights come on...had the same problem and changed the switch fixed the problem...
Posted on Feb 14, 2009
Look for a small electric motor near the accelerator cable and near the top of the valve cover.
It's call IDLE AIR CONTROL (IAC) motor.
It's job is to increase the idle when load is added.
Example: turning on headlight,turning on AC.
Testing it is simple.
Warm up you car for 10 minutes.
Locate the IAC motor
turn on loads.....AC,headlights,etc
The motor should move the idle up
If the motor does not increase the RPM then it can be stick.
Try to give it few gentle taps to free up the gears.
It can be clean if your are up to it.
This electrical motor is very expensive. Please handle it with care.
The other trouble spot are
old accelerator cable
TPS Throttle position sensor
I will do a simple tune up and gas treatment before starting to replace any parts.
Please post reply on the comment window.
Posted on Oct 27, 2009
the track off light will come everytime yhe check engine light comes on. this is normal. you need to have the check engine light checked first.you can go to your local parts house they will scan it for so you at least see what area you problem is in and then you can start from there. let me know lf you find out youe engine codes.
Posted on May 27, 2009
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