I have a 1986 F250 diesel that starts right up and dies in about 5 seconds. It then takes about 3 minutes to start up. Once it starts it runs great. I have changed the glow plugs with no change in the problem. Any ideas?

Thanks

 

It's not your Glo-plugs. They got your engine started, then the engine ran out of fuel!

The Lift pump is working, but the Injection pump isn't holding it's prime.
There's a line loose, maybe an 'O' Ring that's leaking, up on top the engine in the Return lines from the Pump through the injectors and back to the Pump.
Diesel Injection service, sells a kit for this problem. I think it's DIS.COM