Rick is right...again!
...and don't expect that a new distributor cap will solve the problem...if you haven't read my thread (link posted below), you may want to. It all started with difficulty getting the engine to start, just like you are experiencing...and got worse. Here, read this:
Need help with Mallory Uni-Lite distributor/ProMaster Coil combo
One bit of friendly advice...get yourself a spare control module and definitely make sure that the voltage surge protector is installed. When my cap "failed", I thought it had just burned up the center contact on the distributor cap...it had literally burned the spring loaded contact with the shutter wheel (rotor) completely in two...with the kind of additional damage you'll read about in my thread.
Hope you have better luck than I did...I really like Mallory products, but in this case I'm not sure that my confidence is deserved.
Dugly
