I would start by checking the spring in the pressure regulator because its free to do so. Its possible that its taken a set. You can try stretching it by pulling both ends away from the middle a bit. Don't get crazy and stretch it way out, just try to get it to be a little longer.
If that doesn't solve the issue I have to suspect the fuel pump. The pressure regulator can only set the pressure at a certain psi if its getting enough fuel to build that much pressure. If the pump isn't moving enough fuel then the regulator can't build that 60psi because there isn't enough excess volume being pumped into the system to build 60psi. There is probably a way to do a volume test on the pump, but I don't know how to do it, or what the spec should be. Pumps are usually rated in gallons or liters per hour, so the typical test involves cycling the pump on for one minute and discharging fuel into a graduated measuring vessel. You see how much fuel it moved in one minute and multiply by 60 and that's you're volume per hour. It either meets spec or falls short, and if it falls short the pump is bad. The key though is knowing what the spec is.
If the pump is bad I would suggest installing a FASS or AirDog system instead of just replacing the stock pump. These systems are more stout than the stock one and provide a bigger filter and water separator. The filter change interval also goes from 12,500 miles to 50,000 miles. Cost wise its a bit more than a stock replacement, but peace of mind wise its money well spent.
If that doesn't solve the issue I have to suspect the fuel pump. The pressure regulator can only set the pressure at a certain psi if its getting enough fuel to build that much pressure. If the pump isn't moving enough fuel then the regulator can't build that 60psi because there isn't enough excess volume being pumped into the system to build 60psi. There is probably a way to do a volume test on the pump, but I don't know how to do it, or what the spec should be. Pumps are usually rated in gallons or liters per hour, so the typical test involves cycling the pump on for one minute and discharging fuel into a graduated measuring vessel. You see how much fuel it moved in one minute and multiply by 60 and that's you're volume per hour. It either meets spec or falls short, and if it falls short the pump is bad. The key though is knowing what the spec is.
If the pump is bad I would suggest installing a FASS or AirDog system instead of just replacing the stock pump. These systems are more stout than the stock one and provide a bigger filter and water separator. The filter change interval also goes from 12,500 miles to 50,000 miles. Cost wise its a bit more than a stock replacement, but peace of mind wise its money well spent.
