I have a 94 LS400, when I step on the gas there's a slight hesitation and when I hit 20mhp there's like a drop off in power like the key has been turned off but it comes right back. car idles fine.
It's like the engine just skips, just changed coils, plugs and wires 6 months ago.
all fluids ok

 

From what I've read it could be the ECU capacitor problem. Even if it's not the problem, it's a good thing to replace them before they fail IMO

 

check TPS calibration, and that all plugs are seated and in good shape.

lexls.com is your friend.