Rough idle when starting

I have a 2013 4.0L Tacoma that is at 156,000 miles, the truck has been great to me so far but having an issue that I can't seem to fine. When I start the truck on the morning the truck will idle roughly, after the truck sits and runs it will smooth out and drive smoothly like nothing ever happened. This only seems to happen when the truck has been sitting over night or for a few hours at work. Sometime it will throw an engine light and other times it won't. It doesn't do this everytime I crank the vehicle in the morning but it doesn't more mornings than less, when it doesn't do this rough idle it l cranks like it is fresh off the lot I cranked it yesterday and she quickly sputtered out and wouldn't start back. After letting it sit for a few hours it cranked up and idled rough. I have new injectors, coils , and spark plugs within that I installed within a month all oem. I have ran fuel system cleaner through it several times and have been pumping only 93 octane at quality gas stations. I am leaning towards either a fuel pump problem or possibly a fuel pressure regulator, not wanting to just throw parts at it. TIA!

 

Sounds like you are getting a misfire. Have you tried testing the fuel pump pressure on cold start? Hook a pressure gauge to the fuel rail.

 

If you have access to a OBD2 scanner, hook it up and check for misfire codes. If it is happening consistently in one or two cylinders, plan a time that you can remove the plugs from the affected cylinders in the morning and put a camera probe in there to check for coolant. You might have a head gasket leak.