Hey everyone,

I am a recent owner of a well maintained ’93 LS400. Despite this being my secondary vehicle, I have really grown to enjoy it. Sadly, the car died on A couple of weeks ago, leaving me stranded and now has a mysterious no-start condition I cannot figure out. I feel like I've tried everything I can, and am almost ready to give up.

Apologies in advance for the long post..


Issue Description

• Engine no-start condition
• Engine cranks, feels like it wants to start – catches on a little, resultant smell of burned rich fuel mixture or oil
• It did sputter like it was going to start with carb cleaner being sprayed with directly into MAF
• fuel pump , relay, and module all replaced

Background Info

• Engine shut off with no warning or hesitation while warming up following a cold start, as if the key was just turned off
• Was unable to restart it

Vehicle Info/History

• Timing belt and pump done
• Replaced rotors
• I replaced the ECT sensor
• No prior electrical or mechanical problems
• No CELs
• No issues starting, fuel gauge seems accurate
• No prior rough engine operation whatsoever during my ownership

Troubleshooting Performed
ECU

• Replaced ECU capacitors – one of six was touching a harness pin connector on the inside and had a tiny amount of leakage, no damage to PCB observed

Fuel

• Tested fuel pressure
• Tested fuel pump for operation – audible confirmed
• Tested fuel flow visually – fuel flows
• Fuel damper raises, sound of fuel flowing in engine bay

Air

• No sputters with MAF unplugged and car cleaner being sprayed while it starts

It almost feels like the car isn’t getting enough fuel, based on it catching on a little tiny bit, but my tank isn’t empty and the pressure reading also states otherwise. Any help is welcome and greatly appreciated,