1995 GMC Sierra stalling



I have a 1995 GMC Sierra. 6.5L Turbo diesel that has started cutting off while going down the road. Usually I can start it right back up, but some times I have to “prime” it by turning the key on for the glow plugs 2 or 3 times and then start it. I have changed the fuel filter and the one fuel line that looked to be bad. Still shutting off.