0559 FUEL RAIL PREASURE FAULT CODE LOOSES POWER

[gearhead]

Not unless it's thousand or more and it could be the fpr valve also. I have seen fuel filters cause this. Most of the time if the pump is bad the commanded will match at 700 rpm no load. soon as you put 50% or more load the actual falls off, this does not mean for sure it's the pump. The proper troubleshooting must be compleated before the pump is proven to be at fault.