When does an inlet valve fully open?Is it BBDC or after?

I have a timing gear with marks that seem not to be right for my car. My inlet valves are fully open at BDC and taking too long to close.I removed the injectors and the engine is actually compressing into the inlet manifold because the valves are remaining open for too long.I have always wondered my the EGR Valve rattles at idle especially when cold. Later when when hot the idling flactuates by about 50rpm up and down.

It`s a 1.6l. Well the camshaft lobes tell you the valve position. If the toe of the lobe is on the hydraulic tappet or lifter then the valve is fully open. As for the crankshaft I am a sure you very well you get that information from the timing mark on the crankshaft pulley. My issues with the car were lazy take off, EGR valve rattling at idle, Exhaust not burning brownish and remaining blackish a sign for retarded timing.I did a compression test and got 90psi on all 4 cylinders. This was very strange because The engine block was horned and new rings put in. It was losing some compression into the inlet manifold thereby partially compressing the air due to the inlet valves closing very late. Earlier on I asked A QUESTION WHEN DOES AN INLET VALVE FULLY OPEN. You replied with the answer that I know to be right, BBDC.