I have a 2005 6.6 duramax 3500 that just wont start. Code is a p0193 and its injector pump, fuel rail pressure sensor, or fuel pressure regulator code. Injectors are good and no fuel leaks new fuel filter and primer housing. last on my list is the injector pump and the fuel pressure sensor. One other thing it runs like it has lost the turbo no power or ummph in it. But if i unplug the mas air flow sensor it gets its power back. I put a new mas air flow sensor in it and it bogged down so i left it unpluged any thought on any of this. Any help would be verry verry helpfull

 

Have you checked cranking rail pressure?

Sent with a Droid RAZR in one hand and 14,000 volts in the other.

 

Not yet waiting on scan tool but I know my rail pressure is low while the truck is runing. It's under 4500 psi.

 

I have seen a few 05 trucks that the FCA or fuel pressure regulator has stuck on. Even happened to my personal dodge.

It will need 1400 psi to start. Return flow tests will help you narrow it down.

Sent with a Droid RAZR in one hand and 14,000 volts in the other.

 

i did the bottle test for the fuel pressure valve on the driver side rail and all is good. just put a regulator in it thats all good. If i may ask what is the return flow test.

 

measures the rate of return fuel from the injectors and the pump. tells you if the check ball seats in the injectors are bad or in the pumps case if it is returning too much fuel. the bottle test just lets you know you dont have a restriction on the inlet side.

since yours is an LLY the return flow test can even be done on single injectors.

 

thanks ill do some more tests and get my pressure sensor on and see what is going on. Thank you for the help and if you have any other info about the truck let me know.

 

report back what you find, i'm leaning toward it being the cp3 so i would start with injector return rate test to try to rule them out

also did it do this all at once?

 

long story but no started with hard start in the morning but after it got warm no start. put glow plugs in did not help. then the p0193 code came up. changed fuel felter and primer housing. no fix droped fuel tank had good fuel pump in tank was working ond no fuel leaks in the lines. so i bought the fuel pressure regulator after it would not start with starting flood. no fix but it would start using starting flood. runing the fuel rail pressure is 800 psi under what it should be so im thinking its gunna be a injector pump. trying to fix the truck for about one year now so its my nest egg .

 

yeah its going to be the pump or the injectors, return flow tests are the only way i know of to tell which one it is since that 0193 code just says low psi not why