Starts and dies

[Neil Swanson <75377.3445@compuserve.com>]

My 88 5ktq      


Today while in a rush to leave work early for a Drs visit the car would
start and run when cranked but die when the key was released.  I quick
swapped in a fuel pump relay, same thing.

I can crank it while holding my hand on the  relay.  I feel it click when
the key goes on, click when I crank and un-click when I release the key. 
No run!

I'm thinking ignition switch.  I will also check for a problem with teh
crank/flywheel sensor.  We've seen them get covered with "hair" like a
magnet dragged through sand used to do when I was a kid. They don't get a
crank signal.  Wiping off teh hair and the car starts.  But it does start
now so...........

Car has 148K on it, '88 5ktq   Ideas?

Neil