FLD 120 cranks and will not start. No fuel coming from fuel pump.

My freightliner has done this to me several times this week. On tuesday morning I started it and it ran for about 5 seconds and shut off. I finally found the fuse that all my buddies told me should be the culprit. I replaced it, (right by the ecm in an enclosed, weatherproof case, 15 amps.). After that it started. I ran some loads the next day, I haul dirt and asphalt locally and on two occasions it shut off as I stopped at traffic lights. After a couple of minutes, I got it started again. Friday morning, I was scheduled to be at the service shop at 7am. It started, ran for about a minute and shut off. I checked the ecm fuse and it is still good. I took the line off of the fuel pump and cranked and no fuel comes out. I went further back to the ecm cooler plate and took the hose off on the inlet side. I sealed the vent tube on the passenger side tank and blew compressed air into the main tank hoping to see fuel come out of the supply line from the tank to the ecm cooler. Nothing. The tank filled with compressed air and would not let any fuel leave. Next, I moved on to the filter/water separator. As far as I can tell, the fuel line that goes into it comes directly from the "T" that joins both the tanks. Once again, I pressurized the tank and nothing comes out. My question is, if you induce air pressure into the fuel tanks, is there some sort of check valve that prevents fuel from coming out? I have had reefer units before that ran out of fuel and I just pressurized the tank to prime them and the fuel went to the pump with no problem. Are engine fuel tanks different? Does it take a vacuum to pull the fuel out of the tanks rather than pressure? Also, I blew air through the hose that connects to the filter/ separator and air does go into the tank. If the fuel pump is not working, then what is going on? Also I checked the fuel solenoid and it gets magnetic with the key on. I took the actuator off and it moves easily back and forth with the magnet attracting it. I checked the screen/filter under the big screw cover and it looks fine. My next step is to remove the fuel pump and see if i can determine if it is working, I'm hoping, of course someone has had this problem and maybe a solution. To summarize, I'm not getting fuel from the tank to the engine. Any ideas? Thanks

 

Thanks for your suggestions. Today I took apart all the fuel lines, cleaned everything, checked the supply stop valve, it works, put it all back together and removed the little line that goes to the fuel rail. I cranked the engine and now I have fuel shooting of the fuel pump line. But that didn't fix it. Now it is bogging down as it cranks. I can hear a big difference from the way it was cranking two days ago and today. Then my starter soleniod hung up and stayed in the on position, not engaging the starter but just running. Also I have a fuse by my ecm that was blown a few days ago. I replaced it and the truck ran. Now when I check the voltage going through that fuse, it is only .26 volts. one quarter of one volt. I'm not sure what it is supposed to be, but I'm pretty sure they would not put a 15 amp fuse on a quarter of a volt circuit. I think that somehow, power is not getting to the ecm. So tomorrow, sunday, I have to diagnose the starter, and then the ECM. I am thinking of just supplying 12 volts to the aforementioned line and see if it starts working. And to top all of that off, the adhesive that holds the inner shell of the hood to the outer shell of the hood came loose and my hood fell off the truck, nose first into the ground. Now my hood is wrecked. So even if i get this thing going, I have to get a hood. I have to remember to take pictures of this stuff. Thanks again!