2005 LS430 (130K miles) hesitated on acceleration from starts.
Local Toyota dealer recommended Fuel Induction Service (does not include Fuel Injector service/cleaning), and the Iridium plugs were due for replacement anyway.
Did that and not much improvement.
Yeah, new Air Filter too.
If I push the car to 4K/5K RPM, the actual acceleration is much later.

Read about Mass Air Flow sensor cleaning here and elsewhere.
I've had bad luck working under the hood, but decided to try it. See pics.
Cleaned it out using CRC MAF cleaner spray (from Amazon), and the acceleration hesitation problems went away!

The car initially idled at 1500+ RPM right after cleaning, and I did not do the accelerator pedal sequence, or battery disconnect sequence, to reset the car's ECU. Driving for a while on the freeway brought idle RPM to around 700 now.

When trying to disconnect the MAF sensor, the 17 year old plastic clip at the top was brittle and broke, but the connector still fits very snugly without it.
And I almost stripped/tore the head on one of the 2 philips screws securing the MAF sensor; why do they tighten it so much?? Told y'all I have bad luck under the hood. Not as bad as the time a hydraulic hood strut failed and the hood came down on me.

MAF sensor, before/after cleaning


Mass Airflow Sensor in LS430

 

Hi, it's not MAF - it's a temperature sensor. The MAF itself is inside - small little thing.

 

Thanks for the edification, @beercan !
I sprayed the daylights outta there with the cleaner too:

Hard to see wire/resistor in there.

 

Those screws are easy to strip the heads on because they are not Phillips, they are JIS (Japanese Industrial Standard).