Thanks, B120dat. I hadn't thought about the coil possibly being bad.

anb008, it's very rare that a cap needs replacing. 90% of the time they just need cleaning. After you clean the cap, inspect it for black carbon "tracks" (burn marks) between any two terminals (inside or out). Replace it if it has these.

The coil is different, it's hard to tell if it's bad by looking at it. You can measure resistance, but you'll need specs. The best thing to do (to not waste money) is to borrow one of another car, even a Ford or GM coil will work fine if it is the same type (pre-electronic, and uses the ballast resistor). If that clears up the problem, then by all means by a new coil.