2011 Ford Diesel 6.7 - Dies out Under a Load
I have had this vehicle that was towed in crank no start it had a code p2291 Injector control pressure too low cranking. we have replaced low pressure fuel pump on frame rail and the secondary filter. We now had 65-70 psi low side pressure but after priming the fuel system we could only get 550-600 psi high side pressure and it needs 4300 psi to start.
After reading all the problems with the high pressure CP4 pumps we ordered a pump from Ford we installed the pump and still didn't have any more fuel pressure. With the IDS ford scan tool going through many different modes I did a Relative compression test and found cylinder #6 was at 92% when all others were at 100 %. I suspected I had a leaking injector preventing the fuel pressure to get to the 4300 psi to start so I decided to replace all 4 injectors on the drivers side. After replacing left bank injectors we did get the vehicle to start we contacted the customer and informed him that the truck was running and he said you might as well replace the other 4 injectors.
(BE CAREFULL UN- BOLTING THE INJECTOR BOLTS THEY BREAK)
So after ordering a special tool from rotunda, we installed the remaining injectors. Road testing the vehicle, it stalls out on a very steep incline. After 4-5 minutes it starts and runs fine. Back to the shop I test with the Ford IDS scan tool and do a high pressure fuel test it passes step # 1 build up time, but fails step 2,3,4and 5 the drop down times all pass.
Any help would be appreciated
Did you follow the steps of replacing the injectors to a "T"? Including programming the IQA numbers from each injector into the PCM?
Yes we have programmed the IQA numbers
Did you inspect the fuel system for metal contamination? Pull the FRP regulator out and look for debris. If it has metal, the entire fuel system should be replaced.
Yes i forgot to mention that both fuel rails were inspected both pressure control solenoid and FPR sensor were inspected . No contamination anywhere. The only thing i didn't do was run a Fuel balance control test on a road test .
FRP#2 is in the driver side rail. Does it have rust build up in it? I attached a pic.
We have inspected pressure control valve and fuel rail pressure sensor for contamination. They are clean as a whistle. If we have the high pressure fuel pump out of time off 1 tooth do you think this could be our problem?
Not at all! I have seen pumps 90 degrees out of time with no drivability issues. The only other fuel control in this circuit is FRP#2. Its operation is mainly over 1500 RPM. What is the fuel pressure when it stalls and will not restart?
What other testing have you done? There are additional tests to be run if the IDS high pressure fuel system test fails. Also, just so you know, this engine only needs 2030 psi of high pressure fuel system pressure to start the truck. Did you record any pid info when the stall occurred? After you replaced the HP Fuel Pump, how did you bleed the system?
If it stalls on a very steep incline, it almost certainly ran out of fuel. You should have had a scan tool on it while driving, and been been monitoring fuel pressures when the symptom occurred. Likely the fuel reservoir in the tank is not hold fuel correctly, resulting in air being pulled into the fuel supply when the bulk of the fuel flows to the end of the tank.
Have you put flow guage on the low pressure side of fuel system? Also how about tapping into the suction side of lift pump measuring suction while test driving?
Yes it will stall under a load going up a very steep grade but in the shop it constantly will fail some parts of a high pressure fuel test . Road testing yesterday with the Ids hooked up I did have a drop in fuel pressure. It did restart in 30 seconds and I was able to continue up the 1/2 mile remaining of the hill.
Check for aeration in the fuel to the HP pump. If no fault is there, the pressure regulator in the rail likely is leaking. You need to test things instead of just replacing parts.
Agreed. We need more info in order to help out.
The filter on the rail is the most common place for aeration to occur. To many times people reuse the oring or overtighten the filter cap and break the stop on the pump.