My 1989 Ford Econoline 350 7.5 lt. suddenly starting having a problem that I cannot figure out. The engine will start only when I spray "easy start" fluid down the air intake. After I manage to get it started, it runs very roughly and I have to keep pumping the gas pedal just to barely keep it turning. I've replaced the fuel pump and filter (external pump and filter) and there is good gas presure on the injector racks. There is also a good spark to the plugs.
Checked the firing of the fuel injectors using noid tool and they are all signaling that they're opening when they have to.
I also replaced the entire distributor assembly including the ignition module and (I think) fuel injector module. One appears to be inside the distributor and the other one sits just under it. I've also put a new distributor rotor.
What could it be? It's driving me insane. It's not fuel, it's not spark. What to do? Help me Obi Wan!