Yup just did the swap to mine last week, very nice. No gain in HP, but does get rid of the "idle shudder" (after you rev. RPMs drop to about 5-600, then to normal).
There is a test, but I forget exactly what it is.
www.clarks-garage.com has the test / Garage shop amnuel / "D" at top of page and scroll down to DME. (just checked for you, wasnt in the DME section- but it is there somewhere, sorry)
I think the thing that is hanging by a wire is the ?altitude sensor? it is pictured in a thread something like "a little fun" it is first page
, about half way down
What exactly is the matter with your car? A better explanation of whats going on will get more and more people to help you out. Itsa no spark deal I'm guessing. Could be a number of things from the ignition switch, speed/ reference sensors, coil, starter. The DME relay is what people say to check out first- Clarks has that on the site under "DME relay testing"