The grill holes might be charred up, even rusted and I agree with .40 you should replace the regulator valve as it would well be gunked up inside. So rather than get blown to Kingdom Come, junk the grill and look on eBay. There are some good grill bargains to be had, some suitable for propane and they're not expensive either.
You can forget what a person looks like, and you can forget what they say. But you will never forget how they made you feel.