The LS400 I have has taken to just dying on the road occasionally, as in tach drops to zero and you get to coast to the side of the road. A number of times the wife has had problems with getting it to start when parked as well. All the lights and accessories work fine, the engine cranks over nicely, but it won't start (doesn't even sound like it's trying to fire). Of course it works fine for the mechanic, and for us most of the time as well.

So far the only thing replaced has been the fuel pump relay (with a new OEM Toyota part).

Being as how this is an older car, have you guys heard of any sort of data logger that can be left plugged in to the diag port to log the problem when it happens? It's old enough that the ECU doesn't keep a history. Failing that, is there something I can do to get it to generate an error code when the problem happens?

 

u need to hook up a fuel pressure gauge and have it taped to ur windshield and drive it around, when the car dies if the pressure is normal u look elsewhere, if not u know its a fuel delivery problem

 

throw in a can of seafoam into your gas tank the next time you fuel up. it's only 7 dollars and if clogged injectors are causing this, the seafoam might fix it. give it a shot...