11 June 2013

6.0 liter Power Stroke Diesel Fuel System Problem Diagnosis Process

Problems with your 6.0L Power Stroke fuel system? We've shared Ford's official diagnosis process here, the same process that Ford techs learn in training.

in this presentation we're going to

diagnose fuel flow issues on a six litre diesel engine using the Rotunda six litre diesel fuel flow tester this tool Rotunda number 310 193 from T kit 2008 DTF was distributed to all US dealers in July of 2008 and simulates maximum fuel system flow on a fully loaded engine the tool has the advantage of simulating these driving conditions while the engine idles in a repair Bay so there's no need to drive the vehicle when using this tool in addition you'll need the fuel pressure tester adapter rotonda tool number 310 111 a gauge bar or a fuel pressure gauge and a vacuum gauge before we walk through the actual Diagnostics let's take a look at a simplified view of the procedure first connect Rotonda tool number 310 193 to the fuel pressure test port of the on engine fuel filter and regulator and insert the output tube into the fuel tank filler pipe so the fuel passing through the tool can drain into the fuel tank the first step in the diagnostic procedure is to verify that fuel pressure is within specifications to measure fuel pressure at the test port start the engine if the engine won't start please refer to this step in the P

CED now open the quarter turn valve allow the air to purge from the tool then record the pressure at p1 if p1 is below the specification check the clear hose for aerated fuel and engine or key off the ignition if you're unable to purge the air from the aerated fuel inspect for fuel line damage or leaks and repair as necessary in this example aeration was not a concern leave tool number 310 193 installed with the quarter turn valve open install the fuel your tester adapter tool number 310 111 and a pressure gauge at the low pressure fuel pump and filter assembly or the hf CM this configuration will allow you to measure the fuel conditioning module outlet fuel system pressure to install the 310 111 assembly disconnect the fuel return line at the hf CM plug it using the 3/8 inch plug from tee kit 2008 DTF and cap the fuel return inlet to the hf CM with the 3/8 inch cap from the same kit blocking the vehicle's fuel return line in this manner disables the fuel pressure regulator allowing proper diagnostics of the hf CM on engine filter and pressure regulator now that the vehicle return line has been plugged

start the engine or if it won't run turn the ignition on allow the air to purge from the tool record the pressure at p2 and again at p1 with the valve open in this example the pressure at p2 is within specification indicating that the on engine fuel filter may be plugged the fuel pressure regulator may be malfunctioning or the supply line between the on engine housing and the hf CM may be damaged now turn off the engine or key off the ignition a visual check of the fuel line will determine if the fuel supply line is damaged in this example no damage was found next a comparison of the difference between the pressures at p1 and p2 will lead you to either the on engine fuel filter or the fuel pressure regulator if p2 minus p1 is less than 6 psi the pressure regulator is bad if p2 minus p1 is greater than 6 psi the on engine filter is restricted to verify the repair remove the 3/10 1:11 tool and reconnect the vehicle fuel return line then re measure the fuel pressure p1 at the on engine housing test port using tool number 310 193 with the valve open note that p1 now meets the specification now consider this example if the

pressure at p2 was below specification the HF cm filter may be plugged the fuel pickup from the tank may be blocked the fuel line between the tank and the hf cm may be damaged or the hf CM itself may have failed as in the previous example a visual check of the fuel system will determine if supply lines are damaged after confirming that the supply lines are not damaged replace the hf CM fuel filter with the new filter installed remeasure the fuel pressure at the hf cm outlet p2 using tool 3:10 1:11 leave tool 3:10 193 installed with the valve open if the fuel return pressure at the HF cm outlet is still below specification measure for inlet restriction between the fuel tank and the HF cm to do so remove the 3:10 1:11 assembly install it on the hf CM fuel supply inlet and replace the pressure gauge with a vacuum gauge now measure the vacuum at p4 if it doesn't meet the specification repair the fuel tank pickup tube for a restriction and verify the repair if the inlet vacuum meets the specification the hf cm pump is suspect and should be replaced for further more detailed instructions please refer to the PC IDI

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