I've had it for a year or two and this is my first problem.
I'm guessing fuel pump but....
If I turn the key on and off a few times it will start, if I spray starting fluid in the intake it will start, otherwise no-go.

Turn key to start, engine turns over fine-nothing. Turn key off and back on sputters a little-no start. Couple more cycles of this and eventually it fires-up.

I'm a diesel truck guy, do these trucks have a fuel pump IN each tank, I'm guessing so.
I think I switched tanks and got the same resuls but I can't gaurantee that.
Never had a fuel problem with my '90 351 either.
Don't think it's an air filter problem.

 

The only way to find out for sure if it's fuel pressure is to put a pressure gauge on it.

Yes, there is one pump in each tank.

 

I agree with you, sounds like low fuel pressure. And yes there is a pump in each tank. When you turn the key to "on" do you hear the pump run for a couple of seconds? How long since you changed the fuel filter? This probably sounds a stupid question but with you being a diesel guy, during starting or failed starting do you press the accelerator pedal? Have you tried to pull any stored error codes? Have you got a pressure gauge such that you could check the fuel pressure with key "on"?
If nothing else this will give your post a bump.



By Quaddriver,
There is a collar..........removable only by a hydrogen bomb.

 

I have no idea why I didn't think FUEL FILTER duuuhhh!
I'll try that first.
It doesn't get driven that much so I'll try that and let you know.
THANKS!

I do always use the accelerator pedal on my IDIs (pre-Powerstroke) as it opens the fast idle solenoid but I didn't think it would make a difference on a fuel injected gasser.
I can hear the fuel pump run every time the key's turned off and back on.

 

On EFI, during cranking, the further you hold the accelerator open the less fuel will be injected. Handy if the engine floods!

 

Didn't know that.