GM3400 - crank sensor is loose!

I have a 92 Chevy Lumina APV van with the 3400 thats is giving me
trouble.

The van died on me out of town, and the shop I found, as part of their
diagnostics, replaced the crankshaft sensor. It didn't help, so they
put the old one back in. The problem ended up being something with the
ignition, the part thats under the coils I think.

Anyway as soon as I left their shop, I noticed a very slight ticking
that I had never heard before. I had the mechanic come out and listen
to it, and of course he thought I was crazy that I could hear some
"ticking" over a noisy 150K mile GM engine.

That was about 6 months ago. Recently the noise has gotten louder and
once in a while the engine would "hicup" or hesitate for just a
second. Now it will sometimes stall, and not always run right away
again. I thought it was the timing chain but listening/looking at it
again tonight I see the plug that plugs into the crank sensor - and
its just bouncing all over the place! I think the sensor is just

So the shop must have not adjusted the sensor correctly when
reinstalling. I'm hoping someone here has experience with the
crankshaft sensor and can tell me - can it just vibrate loose, or do
you think its been pushed completely out of its socket, ruining the
threads on the block? Do you think the sensor is probably ruined?

I know, its hard to guess without taking it all apart, but maybe
someone that knows what this sensor is like and how its mounted might
have an idea. Its probably going to cost me $100+ just to have it
looked at, then a few hundred more if I have the sensor replaced... so
I'm debating just junking the van, its 16 years old now.

-thanks