Hey everyone..
I recently bought a 2011 Ford Ranger 2.3.. it had a bad transmission so I brought it to a new shop to have it fixed.. they got it done but in the process of screwing on the transmission turbine to the engine.. they made a bad mistake of unscrewing the harmonic balancer on the engine by accident.. all that together caused the timing chain to move inside.. and when trying to start it up all exhaust valves broke and punctured 2 pistons and a cylinder wall..
So now they fixed the engine (On their account) got everything done.. all works great but one thing. When doing a cold start, it runs all good but the problem is when its warm and leave it stay for an hour or so and than try starting it, it will sputter and rattle and run on very low rpm and most of the time shut off.. when I then try starting again itll run great again.. It doesnt show any codes.. engine runs great while driving just that one thing..
I thought it could be a fuel leak but I have tried turnig the key on and off a few times so it primes the fuel rail and than start.. but it doesnt help any.. I am all out of ideas where to look at.. can someone please help me out and point me in the right derection??
I told the Mechanic about it but he claims it use to do that before too.. when im 100% percent sure it didnt.. it used to work perfect..
Thanks in advance for all your help.

 

Could be the CHT(cylinder head temp) sensor
Its between spark plugs 2 and 3 in the valve cover

If you don't have an OBD2 reader then I would get a Bluetooth ELM327, under $20, and the $5 Torque Pro APP for your phone
This allows you to read and clear codes, of course, but also watch Live Data from the computer
This is not Ford tool, ALL vehicles sold in the US or Canada since 1996 and up are required by law to use OBD2, still are in 2023

The Live Data on the CHT sensor may show it is way over temp specs after sitting for a few minutes with warm engine off, this causes the computer to get confused in how much gasoline to add to the engine, so rough start and even stall
But after some coolant circulation the CHT cools off and computer can do normal warm engine start
Just a guess
CHT runs about $30 and you need a long socket to remove and install, so I would check first and then replace if it looks bad

A leaking injector can cause engine to flood out when warm, but would also expect a hard start when cold because fuel pressure would be at 0psi, so would need to do the key on and off thing

Another test
All fuel injected engines have "Clear Flooded Engine" mode
It allows the driver to crank the engine with fuel injectors OFF to..............clear, dry out, a flooded engine, lol
Key on
Press gas pedal down to the floor all the way and hold it down, 0 rpms + WOT(wide open throttle) = shut off injectors
Crank engine over
Engine should not fire/start, no fuel
You can release the gas pedal at any time and injectors will start

If warm engine starts normally it could be CHT or leaking injector, so not definitive just a test

I do this every morning on my 1994 high mile(400k) 4.0l engine to get oil circulated before allowing it to startup