Join the club - there's a 3mm allen key that's been sitting in the valley of my engine for over a year now, quite possibly with some other tools as well :biggrin:
The part that you're describing sounds like the vacuum solenoid for the distributor's vacuum advance. It's supposed to be mounted off the back of the mixture unit, just behind the fuel distributor. It looks like this:
http://store.delorean.com/images/Pro...ium/101116.JPG

