Lexus LS hybrid fuel volume regulator issue

I had something similar happen with my Lexus LS, though it's not a hybrid. Those symptoms sound familiar, especially the rough idling and loss of power. The fuel volume regulator controls the amount of fuel delivered to the engine. If it's not working correctly, it can definitely cause misfires and stalling. Have you checked the high pressure fuel pump by any chance? They tend to fail.

Interesting. I haven't checked the high pressure pump yet. Is that a common thing to go bad on these?

Unfortunately, yes, it's a known issue. The defective high pressure pump can cause the fuel volume regulator to fail as well. It struggles to deliver enough fuel, which throws off the whole system. It's best to get it checked by a professional to confirm. I eventually had to replace both, and the bill was around 1510€. It fixed everything, though.

Thanks for the info. I appreciate it. I'll take it to the shop to get it sorted. Looks like my fuel pump needs replacement.