It is important to cook ribs slowly. There are some other considerations to grilling excellent ribs.
1) pull the membrane off of the bone side of the rack.
2) Put an aluminum roasting pan in the bottom of the grill and put a couple of inched of water in it. Indirect heat seems to be be easier for me.
3) Use a dry rub or salt and pepper
4) Place ribs fat side up and do not flip. Let cook entire time fat side up.
5) 220 - 250 degrees for about 2.5 hours.
6) Do not opent he grill to check the ribs all the time, let them cook.
7) Baste with barbecue sauce after ribs are done, for the last 5 or 10 minutes it is on the grill.
8) Let ribs sit for about 8 minutes before cutting so liquids can redistribute.
Sometimes I pack ribs in rock salt and cracked pepper but scrap it off just before applying any sauce. These tips have always helped me make great ribs on a grill. True mastery only comes with practice but I hope this helps.
Knox Spice Co.