07.5 6.7 won't start. The truck started running bad the died, now it won't restart. I have about 10 psi from the lift pump, and according to my scan tool I have between 10,000 and 12,000 kpa of fuel pressure at the rail. I pulled the fuel line off on the back of the head and I have no fuel coming out of it. I was told if the injectors were bad that alot of fuel would be coming out of that line when I tried to start the truck. I have the exhaust pulled off to eliminate the possibility of a clogged exhaust keeping it from starting. The map sensor reading while cranking is 100 and the mass air flow is reading between 7 and 10 g/sec. Anyone have any ideas?

 

10-12k rail pressure at crank up is unheard of. these things fire off at 5500psi and idle around 6500-7000psi.

check your connection on your fca if you are getting that much rail psi at crank up

the line on the back of the head is a return line. pull the hard line off your pressure reliefe valve and see if there is fuel passing on crank up. if so, your releife valve has popped and returning fuel thru that circuit.

 

welcome to DTR!

 

10,000kpa is equal to about 1,450psi and 12,000kpa is equal to about 1,750psi, so that is where my fuel pressure is at. I am not sure how much pressure it takes to start these engines. I pulled the line off at the pressure relief valve and there is no fuel coming out of it either. Ther is alot of fuel going back to the tank, which I think is normal since the engine is not running and using any of it and the lift pump is stedily pushing fuel to the injection pump. Thanks for the response, I have to get this thing going, I have to go to work Thursday! I am going to pull the fca off here in a few minutes, do you know what size torx hold it on?When I unplug my fca, the rail pressure does not change, should it?

 

5000-5500psi is starting pressures

 

Thank you very much, now I just have to figure out if it is the fca or the cp3 causing my problems. Should the rail pressure increase when I unplug the fca or should it stay the same? The truck won't run so I am just going on cranking pressures.

 

should go to max line pressure with fca unplugged and run like a 12 valve and set a check engine light

 

Ok, thank you. When I unplug mine there is no change in rail pressure at all! I think you just told me what my issue is.

 

when was the last fuel filter change?

 

About 5,000 miles before this happened. That was the first thing I did shen this happened and it didn't help.

 

bummer.

 

Any ideas where to get a fca?

 

get the engine numbers off the side of the valve cover. go to to your local cummins dealer. parts are cheaper there compared to the dodge dealer.

 

I took the fca off and pulled the plunger out of it then put it back on the truck and tried to start it. It started right up but ran pretty rough, I am assuming this is normal.

 

may need a new FCA. probably has a rough spot on the plunger and not allowing it to move freely to make psi adjustments. any codes?