[keithsmusic]

I have lost some of the mortar between the blocks in my foundation. What do I need to do to fix the cracks it is causing. Can you suggest a product?

[CaptainRich]

First, I think I'd check those blocks for settling. Can you see the inside and outside of the wall? Is the cracking due to stress/settling? Is the drainage adequate? There are several products available. Check your local home improvement store (Lowes/HomeDepot), some will not only advise you which to select, but some provide in-store seminars, too.

[glavine]

If it isn't to noticeable id just use some sacrete or quickcrete, unless you want to try your hand at mixing masons mortar and sand,
Other wise id just get a trial and redo the mortar where it needs