Try for ignition gets to pilot lit, then stops, re lites pilot, repeat

If this furnace has a spark ignition to light the pilot, as I suspect it does, remove the pilot assembly then clean the metal rod sticking out of the porcelain insulator with fine sandpaper or a strip of scotch brite pad. Also clean the places where you have metal to metal contact on the mounting bracket. Make sure all wiring connections, especially grounds, are clean & tight.