Powder806

We bought a 1990 Lexus LS400 about 6 months ago. Since this purchase we have bought a new a/c compressor and drier. A week ago, the car died in the middle of the beltway. Not a good thing, during rush hour morning traffic. All lights out, we thought, okay, dead battery. Got a jump went approximately 500 feet and it died again. Thought, okay, alternator is bad. Bought a new alternator and now, it turns over runs for about 2 seconds, then dies again. ANY and ALL help is GREATLY appreciated on this. Called the Lexus dealership, they said we could tow it in and they would put it on their machine to see whats going on with it for a $300 tag plus the cost of the tow there. Sorry, we are not the Rockafellars.
We checked all fuses. All fuses are good. We did the fuel pump test. There is fuel. ARGHHH!! I gotta get this car fixed and sell it. Sorry, patience is not my virtue.

LexLS

First, save yourself the hassle and $300 bucks and read any codes yourself: http://www.lexls.com/tutorials/intro/codereading.html

It sounds like you have at least one code stored. Do any lights on the dash stay on? What does it idle at once it starts?

mick_d_

How secure are the terminals on your battery?

I was having the same problem with my car, start and wouldn't idle, only happened every now and then though. If your unsure, wait till night time and start the car in the dark, if its not secure you should see it arking when you go to turn it over.

garystidha

my bat went dead because of my alternator and after i replaced it and charged the bat it would not idle on its own
if you can keep it running by pressing the gas peddle this should work
keep it running at 500 rpms or less as long as you keep it running under the ideal idle the computer will adjust the idle to where it should be it may take 10 minutes but it was what i had to do
when the battery dies the computer some times looses its basic settings and has to re learn them