94-97 OBS Ford Powerstroke owners have the added potential complication of a fuel tank selector valve in the suction side of their fuel system.
By now, if you have a “Low Fuel Pressure” problem, you should have identified it. As we move into the pressure side of the fuel system, know that if you are still looking for the source of a “low pressure” problem, the only possibility remaining is a massive fuel leak. If you don’t have an…
efore I get into further diagnosis, anyone following this procedure with AFTERMARKET INJECTORS needs to be doing so with a pump that is sized correctly. Depending on the injectors, a stock pump may not be enough, and the cause of your low fuel pressure under load may simply be that your pump is too small for your power level.
If you are diagnosing fuel pressure issues that appear at idle, using the liquid-filled gauge in the regulator may be enough. If your issues appear or get worse under load, it is best to have some kind of fuel pressure gauge that you can see while driving the truck. This can be done with a temporarily installed “mechanics gauge with a hose”, with an aftermarket in-cab electric gauge or with a pressure sensor connected to a monitor screen like an Edge CTS. If you can’t see fuel pressure under load, you are going to have a hard time diagnosing the problem and confirming that it has been fixed.