Rough startup after warmed-up

I have a 2003 tacoma 3.4L 4x4 with 183K on the odometer. I've had an issue for awhile now and I want to get to the bottom of it. When I startup on cold start in the morning or after a couple hours of letting it sit after being ran it starts up fine, but when i go to start it up after letting it sit less than 40 minutes, it will choke upon starting and be very rough and clunky. Routine maintenance is always done, plugs and wires were done less than 15,000 miles ago. I don't have any engine lights coming on either, and it tends to run fine once started either way. Any insight will help

 

I have only had mine a short time. It does the same thing. Warm starts are better if I hold gas pedal down 2 inches. Gas treatment seemed to have helped some but my next gas fill up will be non-ethanol. Curious to see what others here think.

 

http://www.tacomaworld.com/forum/1s...eat-soak-after-engine-swap-3-4l-5vzfe-v6.html

 

I have no knocking or rough idle, the problem is only at startup. I don't believe I am experiencing a misfire