I have an 03 Accent 1.6. Engine cranks but won't start. Replaced fuel pump and filter, cam and crankshaft position sensor, battery, and coil pack. Checked fuses and relays under hood and all are good. Checked the timing belt and that's good. Is there a hidden relay I might be missing? I'm getting everything but spark. No codes because I removed the battery.

crankshaft position sensor maybe , the pcm / ecm - engine computer won't turn on the fuel pump if it doesn't see a input signal from the crank sensor . Your best bet , take it to a qualified repair shop an have it diagnosed .

A lot of things have been replaced ... but there was no mention of checking any fuses or relays.
As an example ... if the fuel pump relay is bad then the car will crank over but not start

Check crank and cam sensor.

P0340 Chrysler - Camshaft Position Sensor Circuit Bank 1 Sensor 1 I would charge the battery with a low amp charger over night.
then check the Cam Position Sensor.
How to Test the Cam Sensor Chrysler 2 0L 2 4L

did you check for voltage at the coil pack low tension input
this comes from the electronic ignition and the distributer dc setting on a multimeter

check inside the distributer that the little magnet is still in place on the rotor and that the sensor is outputing pulses as it turns over
{you can use a meter set to AC range for this ...}
pull a plug out and place its metal to ground check for actual sparks
if this is there then its fuel ...

fuel pump. check injector rail fuel line valve for pressure.

try spraying starter fluid in intake from air filter housing when you crank. if it sounds like its going to start, you have a fuel problem. If not, you have ignition problem. For fuel, could be filter or pump.

is the fuel filter clogged?

Check the ECM if it has the number 1228253 on it, this is what is wrong with it. Gm trashed all of these bad ecms. Get a 16198264 as they do not cause a cutting off problem . Get a delco ecm , aftermarket units will give trouble and may be a rebuilt 1228253 which is junk.

If you haven't done so already, have the cam and crank shaft position sensors checked, or replaced, You have replaced everything else.