Combine the chili sauce and grape jelly in a saucepan and melt. Add the meatballs and simmer for 1/2 hour with the lid on and then 1/2 hour with the lid off.
If you are making fresh meatballs, brown them in a frying pan in hot oil.
Add the meatballs to the sauce and simmer for 1/2 hour with the lid on and then 1/2 hour with the lid off.
Note: I find that if I cook the meatballs longer with the lid off, the sauce becomes thick and sticky, great for a party appetizer recipe.