If you can isolate which cylinder is misfiring it can help to narrow what to check.
The distributor caps and rotors are infamous for misfire issues.
Just because it is new doesn't mean it's not broken.
Make sure the spark plug wires are keeping the spark inside.
A 50/50 mix of water and Windex will highlight misfires observed in the dark after giving the wires a good soaking.
Perhaps a dirty or worn out fuel injector? The spider injectors have known issues. The newer ones without poppet valves are better.
A compression test may isolate an issue.
A leak down test either using a real leak down tester or even the "poor mans" leak down tester.
The poor man's tester is just an air hold adapter. Lock the cylinder you are testing @ TDC with both valves closed. Put air pressure in the cylinder. If you can get 100 to 120 psi in there great!
See where the air hisses out. Out the throttle body is a leaky intake valve. Out the tail pipe is an exhaust valve bad. out the valve cover is to be expected as the rings don't seal perfectly.
Use an Ignition spark tester. At idle or highway cruise the engine is @ high vacuum and the cylinder has almost nothing in it to compress.
This rarefied air/fuel mix can be hard to light. The result is a "partial misfire". This is also sometimes called "lean surge".
A larger plug gap and a platinum tip spark plug can help with these partial misfires.
A faulty MAF or MAP sensor can contribute to a lean miss as can a vacuum leak.
Check the grounds! It's always the grounds!
