Hello, I bought a 2011 F250 6.7 powerstroke at auction. It is a really nice truck. When purchased I had a cylinder imbalance in #4. Going through the M pinpoint test, I discovered it was the fuel injector. After pulling the injector I discovered the IQA wasn't programmed into the PCM. Since I had ordered the new injector, I just replaced it and programmed the IQA. Now the truck won't start giving me a P2291 injector control pressure to low - cranking. I double checked everything. It's good. The only thing I did different from the M test was I don't have the equipment to do a relative compression test. I pulled all the glow plugs and did a manual on all the cylinders using a starter auxiliary bypass switch. With the engine cold I was getting at least 300 PSI on all the cylinders. I don't know if the bypass switch may have killed something. Back the M pinpoint test, I am getting plenty of fuel from the low pressure fuel pump and it's clean. I can pull up the pids and control the F_PCV and F_VCV but I don't know what the lowest duty cycle or highest duty cycle is and I don't know how to observe fuel flow from the left hand fuel rail. How does one do that? What is the lowest duty cycle and highest duty cycle? I changed out the Pressure control valve because it was the easiest. Still P2291. I took the intakes off and looked at the VCV, the screen was clean. I checked all the fuses, they were good. At this point I'm down to two components the volume control valve or CP4 pump. Can a CP4 pump fail non catastrophically?
Any help is appreciated.

 

I was talking to a Ford Tech the other day and he told me that the CP4 doesn't generally just wear out and start causing trouble. He said they go catastrophically and take out your fuel system.

 

I've heard of CP4.2 pumps fail for low pressure and simply get replaced but I believe the truck should generate a code. Having said that I'm assuming your truck was running before you replaced the injector and if so I doubt the HPFP failed as a result.

 

this seems to be like your work caused the no start. Verify all work. I know you said you have fuel but recheck for air.

 

Yes. I did not mention that. The truck ran, I parked it in the driveway so I could remove the wheels and get to the glow plugs. Now no start.

 

I'll triple check. Just so I'm not doing something inaccurate, how do you check for air in the fuel?

 

Did you prime the system? You have to turn the key on for about 30 seconds then off. Repete about 10 times.

 

Yes. That has been done. OK, so there is no funky way of bleeding air.

 

you can remove the output from the engine fuel filter and add a hose to catch the fuel in a bucket to purge air from the fuel system.

There are some threads on her about purging the air from fuel system I think one of them I posted the Ford workshop method of purging the fuel system,

 

Did that originally. I dump maybe a 2 qts of fuel into a 2 gallon bucket just turning the key to on. I bought a fuel pressure gauge and was going to check the low pressure fuel, but I'm pretty sure it's good and fairly positive air is not the issue.

 

Have you checked the connection down by the E brake? It has caused lots of problems for some guys. This sounds like something electrical. Maybe injectors not getting a signal to open. Could be a sensor not plugged in correctly.

 

I was thinking the same thing but though I would get a different code than pressure too low. Could you go into more detail about the E brake connections?

 

I read the VCV is wide open (guessing low duty) at 0 volts. So logic would have at high duty I would have voltage and the valve would be slightly closed. If the PCV is the same low would open and high would be closed. To test my theory, I disconnected the line from the right fuel rail that supplies fuel. I hook a piece of hose to and ran it to a bucket. M test 16 says command the PCV to low duty cycle (open) and VCV at low (open) should observe fuel and high (closed) should not. That worked flawlessly. The VCV works as far as I can tell.
M test 15 says to command the VCV to low (open) and the PCV should flow fuel when at low (open) and stop when duty is high (closed). That did not work. I just put a new one of these on; however, I did buy it off Amazon, but the bag was sealed so... I could not convince myself the part was bad so I wanted to test the connection via multimeter. With the FPL_CMD on and VCV low, I cycle the PCV pid from 0 to 100 and always got approx 7.28 volts the whole time. This maybe one of those instance where you need an O scope since the valves are controlled by the PCM, but I would think I would get a steady voltage if I'm controlling the PID. I just don't know enough to say the wires are good going to the valve.
From that, does anyone have a suggestion?

 

There is a large connectgor attached to the E brake bracket that some folks have had trouble with. The unhooked it being careful not to bend the pins and reconnected it and attached it in a different spot not on the bracket.