Sounds like your multimeter is about as functional as my old Radio Shack unit. Bought it about 28 years ago for school projects and some general purposes around the house.
I still find it handy (when I hooked up my 220V air compressor and found that the house panel was mislabeled
), but I find it to be of little use when attempting to diagnose knotty problems with the engine management system.
Check out the thread about the Sears unit. It's inexpensive and it's far more useful...
http://www.peachparts.com/shopforum/showthread.php?threadid=67067