Brenda~ I dont know if you've ever seen my posts around the holidays when Ive tried to cook a roast....but I have roast issues!!! Im 40yrs old, and this was the first roast Ive cooked that was delicious!!!!!!!!!!!!!!!!!!! Any and all other roasts, including the expensive one I bought thinking that was the problem, turned out like shoe leather!! So here is what I did this time.....
2.5lb sirloin tip roast (on sale) thats why I thought Id try this again
marinated it for a little more than 24 hrs. Just one of those marinade packetts you see at the grocery store, you mix it with oil and vinegar, then I tossed in 1/2 packett of lipton onion soup mix, and a dash of liquid smoke. Let it sit all day, and before you go to bed, turn it over in the marinade.
BBQ.....I soaked some wood chips (any flavour)for 1/2 hr (pick them up at walmart cheap) make a packet to sit over the flame. You want it about a foot long and filled nicely. Poke holes in the top of it, and leave it.
....turn on high and sear all sides of your roast on the grill then turn off, have the far burner on low...the one that has the wood over it. put your roast over a burner and a 1/2 away from the flame. It should be on low, but the internal temp should be at about 200ish.(no flame under the roast!) Leave it!! Go back about an hr and 1/2 later and start mopping your fav bbq sauce on the roast to keep it from getting dried out.

We used a meat thermometer and when it was at med done we took it off and let it sit for about 15 min before cutting into it. It took about 3 hrs to cook

We've been picking at it all day, and I dont think we are going to have enough for supper
It sounds labour intensive, but it really isnt. Let me know if you try it and how it turns out.