BryantWall

I have a '96 Lexus LS400 with 170K miles on it. The car was bought used 6 months ago.

It was running fine with no major issues until one night it just died while going on the on ramp. After that it just turned over, and would occasionally fire but immediately die after letting go of the key. The check engine light is on, however there are no codes when tested.

I've replaced the fuel pump, fuel filter, fuel pressure regulator and i've even replaced the ecm with a "refurbished" ecm.

It's been to two mechanics that can't figure it out. One suggested a security issue and recommended taking it to the dealer.

Does anyone have any suggestions, or should I just buck up and take it to the dealer?

Banshee365

Have you checked the timing? I would also try an inline spark tester on each bank to see. If both sides are getting spark. There are seperate coils for each bank.

brybo86

im going with distributor caps and rotors, one of them took a dump

RA40

iTrader: (6)

Welcome to Club Lexus.

This is a checklist to go through in determining some possible faults:
https://www.clublexus.com/forums/ls4...ml#post8263261

That is a key symptom to investigate. This ripple test to determine if the replaced ECU is properly functioning. There should be a thrown code to get.
https://www.clublexus.com/forums/ls4...-by-yamae.html

Checking the fuses and relays in the engine compartment as well.

dicer

First check for spark, then fuel pressure with no spark or fuel next possible stuff --------> ECU per above and ------->
Cam and crank sensors! Need to check for signals. Caps and rotors do not fail all that often, and when they do its usually arcing over causing a miss etc. Also check fuel pump relay and resistor.

It would be nice to know what the mechanics all checked for.

I think the security system won't allow the starter to work. If it works its not the security system.