slant six cranks but won't start

I'll just copy my answer to the "won't start" post just above yours:

Next time it acts up, run a jumper from BATT+ to coil+, put an in-line spark tester in cyl #1, if it still won't fire and you see the tester flashing bright (good spark), spray starter fluid down the carb throat and try again. If your starter keeps acting up, replace it with a mini-starter from a Magnum V-8 engine (Ram trucks, Grand Cherokee). They are so light and cheap you can carry one in the trunk. If it runs, don't leave the jumper on long or the coil and ECU will soon overheat. Report back w/ results and we'll tell you more.