Nephew driving his Kia and it made a clunk and dash lights came on it died now it won't start it just acts locked up he checked timing belt its intact. Any ideas?

You need an auto-electrician to connect a code reader or a pro grade scan tool computer that can scan data in real time. It will tell what is happening when the car starts to fail.

If it acts like it want to die, but doesn't. Check the air filter and clean the inside of the throttle body.

You could replace the sending unit to cross it off the list of possible problems.
You could check resistance cold and then with the engine at normal temp too. The gauge on the dash could be faulty too.

the next things i would check would be seeing if you have spark from the ignition system , compression in the cylinders by performing a compression test, and checking the timming belt to make sure it has not failed and come out of time.

Check the timing. Before I put anything back together I always start the car and make sure everything is okay. After puting the belt on you always want to rotate the crank two full revolutions to double check your timing. This is of course assuming u did the timing belt because of maintenance and not because it broke.

it is the alternator. 100% Once the alternator goes out it is not uncommon for the lights on the dash to act strange. Go to your local parts store and have them do an alternator output test. Don't go driving too far because when that battery goes dead the car will die also because the alternator is not keeping a steady charge.

sound probably i timing fault, do you have an engine warning light on. as it could be something else but if no light on it could bet the timing belt/chain. would not keep driving if the belt is gone as it will damage the engine. if light is on then you can use a ecu reader to find the faults.

maybe your fuel pump stop working or a blown fuse for the fuel pump or ignition coil. First checked for blown fuses

sounds like a bent push rod or bad starter

Jumped time. If it runs ruff I would do that too much, you could bend a value.

Fairly common problem, you just need a new timing belt.