we have had a 6.0 here at the shop for awhile with air in the fuel system. i checked the fuel pressure as soon as we got it, and it held 52psi koeo. done a visual check on the suply line from tank and didnt see any where that looked to have a hole. pulled tank o check for blockage there, the screen on the bottom of the pickup tube was broke off, the owner waned us to just put it back in the tank and with out the screen. bleed the fuel system again, and the truck started right up. ran a lil rough but was the first time i had heard it run. fuel pressur was sitting at 50 idle and 48 at wot. let the truck idle for about 2 minutes and it died. loosened the fuel filter cap and it was full of air bubbles again. what do yall think? im starting to lean to maybe a sealing washer is bad on an injector.

 

A lot of times the cap doesn't make a good seal down on the HFCM on the frame. Try taking that off, lubing the o-ring really well and reseating it. A sealing washer on an injector is post stream of the fuel bowl, so it sounds like you're getting air before that, but I guess it's a possibility. They really need to be worked hard to bleed the fuel system out too, a quick trip down the block usually wont do it. Needs some good hard WOT runs.

 

ive done resealed the bottom filter.
i was reading somewhere where if the selaing washer was bad, it would allow air to come back up stream
every other truck ive had the filter off, all had to do was bleed the air from the cap and never have any more problems with it.
when i bleed the air it runs for a few minutes, but then it will die.

 

I've never really heard about the injector leaking back upstream, but suppose it's possible.

I've read about numerous cases where guys had issues sealing that bottom filter, and had to remove and reinstall the cap up to 5x. However they only knew to do this because of fuel pressure readings (so if you're reading this and don't have a fuel pressure gauge, GET ONE! not aiming this at you biged, but anyone who reads this and doesn't have one). Seems like your fuel pressure is acceptable. What about one of the o-rings on the fuel bowl itself?

What work was done to the truck? Did it come in for air in fuel, or was something else fixed and this is a cause of that? How did the owner know air was in fuel? Truck just randomly started dying a lot one day?

 

we have a fuel gauge on it and was reading it, stated that in op.

the guy brought it to us becaus eit quit running and he couldnt get it started. and if he did it wouldnt run but fora minute, he pulled fuel filter cap on the engine and would be full of air bubbles.

i done the test like described on the bottom of this page Diesel Technician Society and got more air bubbles than they showed in there video. so im guessing its an injector copper sealing washer.

 

I know you have a fuel gauge, I stated it wasn't directed at you specifically...

I'm sure you'll get more of a response on PSN anyways...

 

thanks for the help though adub