Help PLEASE powerstroke wont stay running

[95nkystroker]

First off hello to eveyrone as im a newb on here. But I have a 1995 f350 powerstroke, the other day i was drivin it and all of the sudden it started smokin geryish black then it slowly started to loose power, then it made a knock noise like it was chokin for fuel or somethin and died. So i had the truck towed home and now here is what its doin. I can get it to start up after almost draining the battery crankin on it for so long, but it will start and idle for about 10 mins and then slowly start to die back off and when it is idling it wont rev past two grand. After the truck dies back off you can hear the fuel tank bubbling and when u unscrew the fuel tank cap pressure is released out of the tank. I had a guy come over and scan the truck for codes and it was not throwin any codes and also the CEL light never came on. I checked the fuel bowl after it died and it was still full of fuel and i also changed the filter while i was in there. Also checked engine oil and HPOP oil and all were full. I have no idea what is wrong with this thing as this is my first powerstroke, Ive been tryin to figure it out for almost two weeks now and no luck and i really need it goin again as its my daily driver. Im bout ready to just throw in the towel and sell it but my wife wont let me. Can someone please help me figure this out

[Fordman247365]

You got a good wife.
I will pass this around maybe find you some more help....

[alberta 7.3]

Check the fuel pressure at the regulator, at the forward/driver's side of the fuel bowl you will see a schrader valve (or rubber/plastic cap over it.) You should be able to use a tire pressure gauge on it to get a reading. Use proper safety precautions around the running engine and for possible fuel spray. These trucks use a 2 stage mechanical pump, so the engine must be running to get a pressure reading. Low fuel pressure won't set any trouble codes, and a full fuel bowl won't guarantee the pump is good either.

Let's try to diagnose this thing with you, rather than just throw parts at it until it goes.

[chvyrkr]

What did the guy use to scan for codes?

[weareweird69]

Also check the fuel bowl for any black coloring. Black fuel filter, or a black residue on the bowl itself on the inside. These are signs of bad injector O-rings, which can cause no power, and white smoke when fully blown.

[gaspipe]

Fuel tank vents plugged? Happens here in the south fairly often when a particular insect chooses to plug your vent hose to make its home.

[95nkystroker]

The guy that scanned for codes used a snap on somethin cant remember the exact name. I check pressure at the valve with a tire gauge and at idle it was about 10 to 15 psi then when you would rev on it the gauge would just jumo around like crazy but never went past 20 and then the truck would start to die back off. There is no back coloring or residue in the filter bowl. But everytime the truck dies you can hear the fuel tank bubble and when you uncsrew the fuel tank it lets off a bunch of pressure and u can hear the tank pop. Also I cant get the truck started unless i keep tappin the gas pedal while tryin to start it. It does smoke while tryin to start. Yesterday i thought it almost looked like there was fuel leakin out of the exhaust where it goes from 3 to 4 under the truck. Idk im compleatly stumped on this one, I would think that even if i had one or two bad injectors the truck would still run. Also the VCH and UVCH on both sides are new. Can someone please help me figure this out today

[Fordman247365]

There isnt nearly enough fuel pressure, 65 psi is the best. Either the fuel pump is screwed or something is blocked somewhere. Does it do it on both tanks?

[95nkystroker]

yes same on both tanks but after it dies there is fuel in the bowl

[weareweird69]

Fuel in the bowl is good, it shows the pump is pulling fuel, but the pump is a 2 stage pump like bill said. It has two purposes.