New Pedestal Sink Not Draining Normally

I just installed a new pedestal sink that drains very slowly. The top of the drain (at the bottom of the sink) is now only about 4" above the wall drain outlet. This is much less distance than my previous sink. My question is there a minimum height differential required betwenn the bottom of the sink and the wall drain outlet? Could this be causing the problem? Otherwise the drain is free of debris, clogs. Thanks for any advice!

Does the sink have an overflow? Is the grid strainer have small holes? Either of these things can slow the flow down. If the trap isn't trying to flow uphill, the drop shouldn't matter much.

Yes, the sink does have an overflow. What is a small grid strainer? What modification do you recommend that I make to make the sink drain faster?
Thanks.

Just make sure your 'pop up' is all the way up.
Try removing it to see if things go better.

If the sink has a stopper (and it isn't internal), that isn't the problem. Some sinks don't, or the mechanism is below the strainer. When the holes are small and there's no overflow, it's hard to get the water to start draining. Sounds like you have a clog somewhere. You might want to post a picture so people can see the arrangement you have.

Make sure the wall arm of the trap isn't too long and shoved too far into the wall!