I had the same problem also. My solution, after days of exhaustive troubleshooting and replacing parts also...I finally bought a cheap fuse test light, and checked the connector that goes into the coil. There was just a little bit of corrosion on one of the wires inside the connector, I scraped it with a wire brush and a finishing nail. I put the connector back on the coil and my van fired up on the first crank.
So, I recommend checking your connectors along your ignition system and removing even the smallest piece of corrosion or rust on them. It worked for me. And it was something that can be easily overlooked.
Lemme know if that helps you out....Good Luck, Buddy.