I have an 85 Safari that will turn over but won't start. It happened the first time 2 weeks ago after a backfire so I had it towed to a friends house. The day after the tow it started no problem, but the timing was out. We put in new plugs, oil, oil filter, air filter, fixed the timing and ordered a distributor cap and rotor. Three days after I started it, started to pull out the driveway and it stalled and would not start. Now it will turn over, and not start. Haven't put the new cap and rotor on since the van won't start. Any ideas with what's going on?