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Discussion Starter #1
Hey guys.. I have a 2006 f350 superduty.6.0 powerstroke. Last week I put on new alternator. Truck been sitting about 3 weeks not started. Once put alternator on it fired right up and ran about 45 seconds to a minute and it quit and will not start. I check the secondary fuel filter on motor there were no fuel. Checked the filter on the frame and it's all black I guess some bacteria in fuel. All fuse good and relay. And the pump on frame runs when the key is on. Is there anyway of checking the pump and seeing if it's good. Cause I'm not getting fuel up to secondary. Any suggestions?​
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Have you confirmed that there is fuel in the tank? I don't mean confirmed with the fuel gauge - I mean have you put a wire in the tank to measure the depth of the fuel remaining? Did you disassemble any portion of the fuel pump/filter assembly on the frame? The correct name for that assembly is "Horizontal Fuel Conditioning Module" or HFCM. If it is not completely airtight sealed it will not draw the necessary vacuum to pull fuel from the tank. If the cover with the water drain plug has been removed and replaced without replacing the gasket it can easily leak enough to prevent the pump from priming.
 

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Discussion Starter #5
Have you confirmed that there is fuel in the tank? I don't mean confirmed with the fuel gauge - I mean have you put a wire in the tank to measure the depth of the fuel remaining? Did you disassemble any portion of the fuel pump/filter assembly on the frame? The correct name for that assembly is "Horizontal Fuel Conditioning Module" or HFCM. If it is not completely airtight sealed it will not draw the necessary vacuum to pull fuel from the tank. If the cover with the water drain plug has been removed and replaced without replacing the gasket it can easily leak enough to prevent the pump from priming.
Yes there's at least 7 gallons of fuel in it. No I didn't take the HFCM apart. Only thing I did was took the filter out of it. Will it shoot fuel out of it if I left the filter and cap off from it? Cause I tried that to see if fuel come running out.
Have you confirmed that there is fuel in the tank? I don't mean confirmed with the fuel gauge - I mean have you put a wire in the tank to measure the depth of the fuel remaining? Did you disassemble any portion of the fuel pump/filter assembly on the frame? The correct name for that assembly is "Horizontal Fuel Conditioning Module" or HFCM. If it is not completely airtight sealed it will not draw the necessary vacuum to pull fuel from the tank. If the cover with the water drain plug has been removed and replaced without replacing the gasket it can easily leak enough to prevent the pump from priming.
Im going to do the priming on it the way it says to do. I didn't prime the way it says turn key on 30 seconds 6 times. I'll try that and if that don't work then it would have to be the lift pump inside the unit cause I tried and tested about everything else. Any suggestions
 

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Sometimes the fuel pickup tube fails at the vacuum relief valve (at about 1/4 tank level) and it will draw air in and it won't pump.

7 gallons is about 1/4 of a tank.

That said, the primary filter in the HFCM shouldn't be black unless you have some bad fuel. That bad fuel could have clogged up the pickup tube or the pump suction line.

You might want to disconnect the fuel lines at the HFCM and see if the pump will draw clean fuel out of a bucket and pump it up to the secondary fuel filter.
 

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Discussion Starter #7
Sometimes the fuel pickup tube fails at the vacuum relief valve (at about 1/4 tank level) and it will draw air in and it won't pump.

7 gallons is about 1/4 of a tank.

That said, the primary filter in the HFCM shouldn't be black unless you have some bad fuel. That bad fuel could have clogged up the pickup tube or the pump suction line.

You might want to disconnect the fuel lines at the HFCM and see if the pump will draw clean fuel out of a bucket and pump it up to the secondary fuel filter.
Thanks I will try
 

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Discussion Starter #8
I'm going get some more fuel now and new filters and try that. Thanks a Lot. Will let ya know resultsl
 

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Yes there were no fuel in secondary filter. Shouldn't there be fuel come out of the pump when u take filter outof one on frame. Cause there wasn't. I even cycled the key with the filter outof the pump on frame and it still didn't shoot fuel out
If you remove the fuel filter from the HFCM on the frame it WILL NOT draw fuel from the tank. Two things: First, the filter when installed and the cap is screwed on COMPLETELY pushes open the fuel pump inlet. Second, if you lef the cap off the HFCM and expected to find fuel squirt out I can tell you that it wont. The fuel filter and cap are n the suction side of the pump.
 

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Discussion Starter #10
Thanks alot. Did notknow that. I'm going now to get more fuel and try the eight way priming that just learned. I'm a deisel virgin only had this truck almost a year and learning more aboutit everyway. Already put over$6000 in it. But I love the truck. Thanks and will get back let ya know what it was
 

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No. The HFCM on the frame rail pumps all of the fuel it draws through the primary filter directly to the secondary fuel filter on the engine. Fuel returning from the engine returns to the HFCM and depending on the temperature of the fuel, it either recirculates that fuel back to the engine or back to the fuel tank.
This was from the closed thread where I wasn't completely clear in the post you responded to but I don't believe this is completely correct either. I believe what actually happens is that the fuel flows from the primary filter to the secondary HOUSING and then is either bypassed through the secondary filter and on to the injectors or returned to the HFCM and thence to the tank. My point was that the primary filter can plug very quickly after a bad slug of fuel because the tank is effectively polished on a regular basis but that polishing only affects the primary filter. In the context of the OP situation he needs to change his primary filter when it gets dirty, regardless of how recently he may have changed it.
 

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This was from the closed thread where I wasn't completely clear in the post you responded to but I don't believe this is completely correct either.
No again. Since you apparently are just guessing, here is the fuel system schematic showing fuel flow through the entire system. Begin at the fuel tank at the lower left corner... the arrows show the direction of fuel flow. It should now be quite clear to you that no fuel is directed back to the tank or bypassed before it returns to the thermo recirculation valve. There is no "polishing" of fuel or filtering of fuel in some pointless loop from the primary filter... or the secondary. As far as the secondary filter is concerned, any fuel that is not sent to the engine and injectors is spill off from the air bleed orifice and the fuel pressure regulator.


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If you remove the fuel filter from the HFCM on the frame it WILL NOT draw fuel from the tank. Two things: First, the filter when installed and the cap is screwed on COMPLETELY pushes open the fuel pump inlet. Second, if you lef the cap off the HFCM and expected to find fuel squirt out I can tell you that it wont. The fuel filter and cap are n the suction side of the pump.
Thanks for your post with the diagram. So many people do not realize that the filter and cap are on the suction side. They have a hard time understanding why a loose cap or bad cap o-ring can pull in air, but not leak externally!
 

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Thanks for your posts. So many people do not realize that the filter and cap ore on the suction side. They have a hard time understanding why a loose cap or bad cap o-ring can pull in air, but not leak externally!
And unfortunately the most common human error I come across is simply a 6.0L primary filter cap that is not screwed on all the way.
 

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No again. Since you apparently are just guessing, here is the fuel system schematic showing fuel flow through the entire
Actually your diagram completely confirms my earlier explanation. Since you seem incapable of understanding the information you claim to work with I'm done here.
 

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Discussion Starter #16
Hey guys want to give a shoutout to thank everyone that helped me get my F350 back on road.
 
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