Using a jumper wire, ground the fuel pump connection on the diagnostic connector.. With the ignition ON the pumps will run continuous as long as the ground is connected. It takes the PCM out of the diagnostic (PCM controls pump ground/run function) and can help trace power distribution on back to the pumps since the pump run time is regulated by the PCM. When connected, you should hear the fuel relay 'click' and a distinct hiss as the rail pressures.. You can also check for 12v IN/OUT of the inertia without power distribution timing out. Check both positions on the tank selector switch.. If the filter was restricted, chances are the system would pressurize and start, but would soon stall after the available fuel/pressure was spent..

 

....certainly,,change the fuel filter..and you're right about the fuel pump location....both the low and high pressure pumps are there in the tank.The van has the pump underneath,on the frame.

 

THX, for your help. Both fuel pumps could not be bad. If the fuel pressure regulator was at fault/bad would that have a no start effect? again, Thank you..

 

Most likely correct on the two pumps,

So,,, they do run, you can hear them? If your not hearing the pumps run, or have any fuel pressure at the rail schrader, first thing I'd do is check for power distribution 'at least' through the inertia switch. If you have 12v 'both sides' of the inertia, good chance the pumps should run since it proves out fuses and relay function, as well as a closed inertia.. Unless the harness on back is open, or if the fuel was rotten/varnished, either could be an issue with the pump function.. If you ground the DLC and the pumps DO NOT run with KOEO when each are selected, test for power through the inertia, then back at the tank connector. If power at the tanks, and still no pump run, next step may be to drop a tank, more so if the filter shows heavy trash/debris.. If the pumps DO run with the DLC grounded, and still no pressure look at the filter if you havent already. You can also 'carefully' take a fuel volume/pressure test pre filter.. I wouldnt condemn the filter or regulator or a system full of trash until I verified power distribution on back, and run test the pump/s DLC grounded checking for pressures on both pumps on the schrader, or pre filter if possible..

 

Hi, Thank you. I'll try these suggestions, and post results. Again, Thank you..

 

I'm new to this so I hope this where to spill the question. I have an 03 f350 w/7.3. I have cold sart issue. First batteries are new, alternator year old, new glow plug relay. When cold starting in a.m. sometimes fire right away other times needs extra cranking. Either way once fires it runs rough like gas engine with bad plug/wire. I can let it warm up or drive right away. In about two blocks at steady trottle its like someone flips a switch and runs smooth. Rest of starts thoughout day no problems.

 

Sounds like it's time to check each individual glow plug.