7.4l 1989 cranking but no fuel

[Valechar]

Hi, first I need to say at everyone that I'm French and my English is bad ?. 

 

I have a chevrolet 1989 C3500 with a 7.4 engine. 

I drive on the highway when my truck stop like if I turn the key off. The two tank was full of gaz, I start and the engine crank so the gaz doesn't run to the throttle. Someone has the same problem in the past and can help me? 

[GMCPaul]

Probably a bad fuel pump in tank. Listen near fuel tank as someone turns key on to run position but not fully to start and you can normally hear the fuel pump come on and prime system with pressure.