I must have read 300 threads over the last year on the Fuel control Actuator before I took the plunge. I had no codes for anything in the fuel system.

I had been wondering about the funny quirks my 06 5.9 truck has had for a long time. It had a funny rhythmic vibration at idle when hot, the turbo lag was getting longer, it had a pinging like a gas motor at throttle tip in and half pedal, it had a light lope to it when it was really cold outside and lastly the fuel mileage on the overhead was slowly falling. A couple of times I had dead pedal when I left a light. Power was still there, I've been across the scales at 19000 lbs lately, truck didn't seem weak with the foot down.

I had read about all the checks for the FCA, stuff like if it rattles its good, if the idle goes up when its unplugged, if you put 2 stroke oil in the fuel and it runs better etc. Tried all of that, it past all those tests, on the scan tool it showed the fuel pressure off target from 300-400 psi when hot, found a lot of posts claiming if it's within 500 psi of commanded pressure, it's working properly.

Well I bought a genuine Bosch part from Rockauto, and the truck now runs like it did when it was new. No rattle, no pinging, no vibration, no lope, no dead pedal , lag is almost non existent.

On the scan tool, the rail pressure is now <100 psi different. than commanded. The old FCA still hit high peak rail pressures, it just fluctuated back and forth over setpoint.

I had read about people claiming that retiming the injection gear gets rid of the fuel rattle noise. It doesn't look like thats a real fix, one might be just retiming the out of cycle fuel pulsations caused by a hunting FCA.

The FCA was original, truck has 585,000 km's on it,I wish I would have just changed it at 500k.