No RPM's and the Overdrive

Check for a fuse if you didn't already.

Check you catalytic converter.

I would either go to a shop or buy a Infrared Thermometer and check the temp of the radiator and the upper radiator housing temp, that's a nice car and expensive to repair, but to blow the engine it would be worth nothing

The problem could be the contacts in the solenoid. The starters are not that expensive but to getting to it is very extensive. It is under the intake manifold. I had been having problems with my ls 400 (1990 with 275K miles) engaging the for quit some time and milked it out as long as I could.

fuel pump presure needs checked as does the fuel filter. injectors fail commonly and theie easy to test with a scanner just turn them on and off one at a time

Here is a diagram that should help you out.

I have the same problem with my 94 LS, its getting fixed now. The camshaft sensor is telling the computer that the timing is off, meaning your timing belt is either jumping or missing teeth, or it may be going bad. It is a very big job, so I suggest replacing the belt, water pump, tensioner, and maybe the seals and pulleys as well. Are you at a lost of power, has you car ever cut off at a stop red light or when driving?

have the insturment cluster checked. known for going bad.

1993 Lexus LS400 wont idle but will run

when should i drive in overdrive