So I have a 15 elantra 1.8 that misfires when starting it in the morning and accelerating to roughly 4-5k. The misfire will keep going until the vehicle is either shut off and sits for a while or its warmed up a bit...letting sit a while and then starting it up again, the misfire will still occur at high rpms. But no sign period of misfire when vehicle is warmed up. Vehicle has 70k miles. So far the vehicle has new plugs, new injectors, new valve cover gasket, new crank sensor and I even swapped coils. I performed a function test on the oil control solenoids for timing and the exhaust one actually failed. Installed a new one of those and problem still occurs. Checked coolant temp sensor and seemed to be working fine via data list of scan tool. Tested compression and static compression is 130 psi for all four cylinders. Checked "running compression" and got roughly 60 psi across the 4 cylinders after 9 cycles give or take. When it was cold, I tried spraying throttle body cleaner around cylinder 4 to see if I could get engine to act sporatic at idle but nothing. Checked fuel quality and quality was good. Next, I then checked engine idle vacuum. Roughly 18 inches of vacuum. Im sort of stuck on what to test for next before I let the dealer take it over. Does anyone have any idea what it could be? Cracked valve spring? Variable intake motor issue? Sticky/carboned valve?