I bought a 1995 LS400 with almost 100K miles, at the beginning work normal, few days after start showing several cylinders misfiring. I check the spark plugs, one had coolant and another oil. I disassemble the engine and found that he head gaskets were bad. I had change all gaskets and seals with original Toyota parts, new injectors and wires, other than the head gaskets the engine was very clean and after the replacements the compression is at the specifications in all the cylinders. all the hoses were check and the damaged ones changed. After the repairs the engine start normal and run in that way for a couple days.
One morning when I started the engine, suddenly the idle became erratic. fluctuating from 400 rpm to 2000 rpm. . I changed the TPS with a generic one. this seams to fix the problem, but few day later the problem change to start at high rpm 1400, the transmission shift out of time and rough, lack of power and hesitation at acceleration. I change the TPS again with a original Toyota and same exact number; again, this seams to fix the problem.
Now some times when I start the motor, I know is going to work normal until next time; and if I let let it to warm-up normal will perform perfect. every time I start the engine when is warm (if I go to the store) start having the same problems; high idle at start and die when I stop. driving with both feet avoid the engine die when the car stop.
It is not engine light. no codes. I was reading that many Lexus owners have the same problems, and are many solutions (or non). I also have another 1995 LS 400 with over 230K miles and has no problems.
the next suspect is the computer, but I'm tired of working in this car and changing parts and the problem persist.
There is anybody who can give me some guidance?. will be very appreciated.
