Hello,Gentlemen
I have a 2004 6.0 I had changed the oil and fuel filters last week and truck has not ran right since.When truck is cold it does not want to start it sounds like it is sucking air so I ran two full tanks still same problem but blew fuel pump (frame rail)so ordered new one put on and same thing sounds like air getting in the line some how no signs of fuel leakage.Hooked up temp fuel line from pickup back of new fuel and took of line that geoes to motor and turn key and looks like a rootbeer just poured nothing but air.Took off cap seated o-ring with vasoline and still same thing.Its driving me Krazy,please help.

 

Are you running a good brand of filters? I had a similiar problem a while back. I bought some cheap filters at autozone. 2 weeks later I lost all power and died. The only way I could get it started was bleed the secondary filter cap. It would hiss like opening a 2 liter of coke. After a week of trying everything, I mean everything, I decided what the hell Try the filters. The filters I bought had a really crappy water barrier that dtereated. But ran fine after I changed them out.

 

Thanks, but I went to ford and purchased factory ones still same thing.

 

Sorry, Could it be a pin hole between the tank and pump? Or a something in the tank?

 

checked from pump on back and nothing

 

You might PM big angry hillbilly. He is a tech that knows his stuff

 

skip59, did you ever find the solution for this? My F-250 developed the same exact problem. The problem got worse and worse until the fuel pump died. I tried everything mentioned here (and more). I installed a new pump and filters and same problem. I bypassed my fuel tank with an external tank, but same problem. I was just wondering, did you ever find a solution to your original question to this post?

 

Get a Fuel Pressure Gauge Gents. It will save your , fuel pump, or injectors one of these days

 

I have the same problem with my 2004. I took the supply line from the tank to the pump off and coneected a piece of clear vinyl hose to the inlet of the pump. Then I took the outlet line from the pump off and connected another piece of clear vinyl to the outlet from the pump. I put 2 gallons of clean diesel in a bucket and put both lines in the bucket. I turned the key on and started the pump. It picked the fuel right up, but when it came back out of the pump, it was full of air. So I know that the air is entering somewhere in the pump. I just need to figure out where. I did recently change the fuel filters and the sales guy gave me Puralator filters. Both of them turned out to be the wrong filters, now I'm wondering if the o-rings were bad also. The only thing I haven't re-replaced is the o-ring on the fuel pump!! HHHHMMMMM

 

Key off, open the drain on the HMFC let it drain.
KOEO wait til the fuel pump shuts off, open the cap on the 2ndary fuel filter housing let the air hiss out. Shut key off wait 10 seconds. do it again.
Then crack the lines going to the heads, just because you got air out of the housing doesnt mean you got it out of the other lines. crack every line open 1 at a time 2 times a piece comming off the fuel filter up top, see what that does for you. And yes aftermarket fuel filters will do that too deteriorate mess with fuel pressure, and even the whole filter come apart.

---AutoMerged DoublePost---

WORST case scenario, you have combustion gasses feeding back through the injectors. Pull the ficm relay have someone crank the engine, if theres bubbles in the housing bingo, compression gasses feeding up through the injector(s) on one bank or another, next step sounds silly, is a balloon test where you remove the lines that feed the heads from the housing, get balloons and zip ties. have someone crank the engine and see if the balloons swell up with the engine cranking. To isolate it to which cylinder it is, remove the glow plug harness and all the glow plugs except 1. Move the glow plug from cylinder to cylinder when the pulses in the balloons stop you know that cylinder is good, if the balloon(s) get bigger from cranking then thats the cylinder thats giving you problems. From there id pull the valve covers, pull the injector(s) that are going south and look at the copper crush washers at the bottom of the injector to see if theyre intact, inspect the lower o ring gasket to see if thats missing and to check for blow by. If you have a bad copper washer it will allow the gasses to leak up and even blow the injector and hold down out. At that id install a new injector cup and to be on the safe side a whole bank of injectors if thats what you find.