Blue spring upgrade killed my fuel pump?
 

Hi guys,

My 6.0 died on me while cruising the interstate a few days ago. Could start it again, ran a bit rough and had no power, a minute or two later it ran perfect again.
Got back home parked for the night, my wife took it the next morning, ran fine for ~15 miles then it lost all power and have a rough idle (she drove it back home). Now it won't run fine again.

Anyway, after reading a lot of similar issues described in the forums here I started to look for issues. FICM voltage perfect 49V constantly at all times, then over to fuel pressure.

After running circles around town before finally finding some adapter to get the pressure sensor into the 12, 1.5 test port I turned the ignition on. Nothing (0 PSI), started it, still 0 PSI.
Taught my pressure sensor was bad, so removed it and left the plug open, turned ignition on, nothing came out. Turned engine on, still nothing (but it ran, a bit rough but ran)...
Removed the filter cap (front filter) and turned on the ignition with the filter housing open, no fuel flowing at all....
Measured voltage in to the fuel pump (on the HFCM), 9.5-11v (seems to change over time?). But can not tell if the pump is working or not.

Should the fuel pump make some noise? Vibrate? when running? And does it always run if given voltage? Trying to make sure that the fuel pump is my issue. But then how could the truck even run if that thing was completely dead?


Blue spring upgrade, + the other standard maintenance (including fuel filters) done around 500 miles ago. Could the increased flow resistance the tighter blue spring gives me have killed the pump?

Any ideas?

Thanks in advance, and thanks for all the useful threads (essentially where all my 6.0 knowledge comes from)!

if the pump is running you definitely hear it I can hear my pump run in the cab with the doors shut and windows up so if your pumps working you should hear it

The spring won't hurt the pump, the stock spring used to hold the same pressure as the blue spring but they found that the spring would loose "spring tension" quickly, around 50k miles.

Thanks!

Would disconnecting the fuel line from the HFCM to the front filter housing and manually feeding 12 volt into it trough the HFCM pump connector give me a definite answer? Or is there some other "control" as well as there are 3 connectors to the HFCM?
The truck still starts up but runs bad, seems strange if the pump is completely dead.

And more important, if it actually is broken do you guys recommend getting a OEM HFCM or going to an Air Dog II or similar system?
I have just done some basic "bullet proof" mods, and don't plan to do any performance mods. But if the Air Dog II is more reliable...

The stock is the most reliable, also what happens if you are traveling and an aftermarket pump goes up?? chances are there will be a Ford dealer closer then a dealer that sells the same aftermarket pump you put in. the pump motr connection is the one closest to the front of the truck, the one on bottom facing the trans on the front side of pump is the Water indicator, the one towards the back and on the bottom is the heater/the new pumps delete the heater so you will just have to tape that connector off. I would check the fuses first and there also might be a relay for the pump. You can remove the whole housing pretty easy as long as you have the fuel line tools, thnthee are just 3 or4 bolts to take off from the other side of the frame, I take mine out every 50k just to clean out the inside as you will be supprised at the crap that builds up in there even when you change filters frequently

Thanks for your help and support guys!

Got the old pump out today, but when I inspected it and fed it with 12V it ran :/
So now I'm confused, I get no pressure at either the test port or at the top of the front fuel filter (nothing!). And I measure power in to the pump when assembled on the truck...
So I'm a bit confused right now...

P.S is there a trick to remove the pump without removing the front drive shaft? Could be good to know for another day ;)

---AutoMerged DoublePost---

Oh, and a tip for all your other guys.

DO NOT remove the frame mounted fuel pump if your truck is standing nose down in a hill, it gets messy...

:argh: good point on the down hill idea,,, Yes I always unbolt the front of driveshaft and tie it up out of the way.

Have you changed the HFCM filter lately??

HFCM filter was changed ~500 miles before the weird loss of power first happened (now it never get's power at all).

Found a reasonably priced HFCM should have it on Tuseday, and can see if I get some fuel pressure with that one. My thinking was that even if the old pump did run, perhaps it did not run "good"...

A quick update,

A new HFCM and the fuel pressure is back and the truck runs like a charm again. Hope you guys had a good 4th, and thanks for all the assistance!

P.S Still don't understand how it could run at all with a broken fuel pump.