p008c casusing symptoms of bad HPFP?

option2

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First off i have an 08 f250 fully ******d, black maxx, s&b intake full sinister kit, 4in downpipe 5in from there back, recently ive been throwing a p008c code(fuel pump cooler open circuit) and me being an idiot let it be because it didnt seem to affect anything. Now the past few weeks the truck has been surging fuel pressure all over the place. If i watch set my H&S to rail pressure it goes batcrap crazy. I replaced fuel filters, and even had a FASS Ti 150gph lift pump installed hoping my factory lift pump was the culprit, i had the diesel mechanic whose highly recommended in the diesel circles around here check the it over and he said the fuel cooling system was over half low, now the pump isnt squealing or making any noise (ive heard the banshee wail they can make when they go bad) my main question is now that the temps are higher (upper 80s-100) latey here in ND could this cause my fuel surging problem? i want to be sure before i pull the damn cab and have a new k16 put in, tomorow im going to tear the drivers wheel well out and see what i can see but a little insight would be great, i figured id ask the pros on here before dropping money im saving for the single conerversion/studs/up pipes/trans on a pump i may not need. Thanks for any help guys. its greatly appreciated

Edit: is there a way to test the pump itself with a multimeter? im pretty damn sure its not working but i dont believe the H&S gives me the capability to monitor fuel temps, but from the research ive read with this code its often a bad wire or connection and sometimes a shorted pump, i just want to narrow down my options as it needs to be replaced eventually anyway
 
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It is typically the fuel cooler coolant pump, from what i have seen. It is mounted on the lower fan shroud, on the drivers side. Take a test loght or volt meter and measure voltage across the pump, if you have 12v, pump is bad. That may cause the issue, due to frt getting hi, or it could be completely unrelated. If the only code you have is for the fuel cooler pump, i would diagnose that before throwing thousands of dollars at it.
 

option2

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You know that never even dawned on me. I haven't got a single rail high/low pressure code. I did once when it was acting up really bad leaving the rig, I was almost to town so I filled it up with cool, new fuel and it ran great. Now that I'm thinking about it I bet my factory lift pump was fine, it would just get down to 1/2-1/3 tank and the fuel would be heated up from long drives to and from work.
 
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I believe the injectors and pump is sensitive to very high fuel temps which is why they installed a fuel cooler. Unfortunately you don't know the fuel temp to see what they are reaching. Also I believe when the ECU detects fuel temp 155c and higher it starts to limit power/torque. I use the Auto Enginuity to active the cooler pump to test it.
 

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