XCross69 - When you are checking the distributor cap, look inside the distributor and under the cap and look for any lightish colored irregular (zig-zaggy) lines. If you see any, check where the cap and distributor meet and see if it appears that the seal is breached near the lines. This happened to me when I lived in StL years ago - the humidity can get in there and interferes with the spark distribution, and can actually cause arcing inside the distributor. Whichever piece of the distributor shows the wear, replace it, or you may want to replace the distributor entirely.
And if you so the fuel pump check as mbeach suggested (letting the fual pump into ta bucket, remember - safety first! - keep your cigarette in our mouth, not in your hands! ;-)