This GS300 has been with me for 20 years, and I'm not sure what's going on right now. It's lived a good life though, 275k kilometers.

For about a month now, the car has been shutting off at stops, this would happen at the start of the trip.

ie. Just started the vehicle, and I drive up to a red light. The car will shake a bit, feels like a newbie shifting gears roughly, then the engine's RPM will drop very low and shut off. I'll have to flick the keys on-off a bit, and I'm going again.

I've been repairing the vehicle bit by bit, such as replacing the battery, which did improve the performance, however it did not fix the problem. Just a few days ago it got pretty bad...

>I turn on the car, it shakes frantically. I hold the brake pedal, the engine's RPM will go up and down, up and down, up and down, chugging kind of. The emissions are terrible too.

Is it repairable? Common? Any ideas? Or is it finally time to buy a new Lexus

Will post a video soon.
Thanks!

 

Sounds to me like throttle position sensor, dirty throttle body, dirty EGR. Even could be an old coolant temp sensor...

 

When was the timing belt changed last? Any codes?

 

Sounds like ecu. Have u checked the actual ecu for possible damaged capacitors?