2005 6.0 cracking injector nozzles?

[bags1010]

I am working on a 2005 F-550 with the 6.0 with 140,000 miles on it. Did the EGR cooler block off and cleaned the turbo and Swamp's Diesel rebuilt the injectors. The truck ran about 1,000 miles and then cracked #8 nozzle. Swamp's replaced the injector and then another 100 miles #7 injector nozzle cracked. Swamp's again sent me another injector and it ran fine for about 2,500 miles. Then about a week ago #1 injector nozzle cracked. I went to Ford and put a Alliant injector in. It lasted about 800 miles and it is cracked now! I have spoke with Swamp's and several other injector guys and no one can tell me whats going on. My fuel pressure at the filter is 52 psi. There has never been any water in the system that we know of and the fuel comes from the same place all the other work trucks fuel up at. The key is also cycled on and off to build pressure on the initial startup. There also has never been a programmer or anything on the truck...Basically just a stock work truck. I just do not want this to keep happening.

 

[dukcaln]

Sound like my issue I was having with my 03 6.0. kept dropping injectors...cracking the tips....mine ended up being a cracked head that allowed coolant into the cylinder and kept craking injectors. finally went all the way and destroyed the rings on the piston. Check for leaks and do a compression check of each cyl....check coolant for signs of fuel. added coolant in the cyl will cause steam and heat up the tips.....destruction is not caught in time

 

[bags1010]

OK...after a bit of experimenting...I made a fuel pressure gauge that comes from the top of the filter housing up through the hood and just kind of sits besside the windshield wiper. Now with the truck just idleing...I have 45 psi. I go and drive the truck a few miles and nothing changes. I leave it idleing for about 30 minutes and come back and I have 5 psi!!!!!!!

It seems that the fuel pump is getting hot or something is changing in the regulator to cause this. I went ahead and installed a new unit and it is staying the same 45 psi all the time. I believe that this was causing the injectors to fire without fuel in them and the metal to metal contact is what was cracking them. The truck now runs the same as it did before and has all the power it did before, but the pressure is not changing now. I hope that this is what was causing them to crack.

After I had the truck all together...I took the filter/pump housing apart and the regulator housing side of it was full of very small pieces of plastic and aluminum. Only place it could come from would be the tank or flowed back from the engine. Maybe this is what was keeping the regulator open and allowing fuel to flow past it right back to the tank?