Airdog problem

[DHayden]

Had my truck running a while back and took the fuel cap off, noticed that there wasnt any fuel going through the return line back into the filler neck. Usually there is a large amount of fuel going through the return line from the air dog to the filler neck. If the truck is running or I bump the starter I still show 16-18 psi. I have called pure flow several times in the last month and STILL no call back with an answer. Any thoughts?

 

[Bob Cochran]

Wow first I have heard of a problem with the AirDog. I honestly cannot think of a reason you are not getting fuel from the return line. I never looked either just happy with the PSI!!! Let us know waht u find out.

 

[DHayden]

Nobody has thoughts on this? How can it be providing pressure? If the airdog was providing pressure fuel should be returned, is there any way the engine pump is supplying this pressure? Does the engine pump give that much pressure? I'm under the impression the engine pump only pumps if the engine is on so if the starter was bumped it wouldnt provide pressure right?
OK this sounds stupid to me but I'm no fuel system expert so...

 

[jakprince]

Maybe 16 psi is all its able to put out. What i mean by that is fuel is only going to return to the tank if the pump is putting out more than the 16psi or so that it takes to open the relief valve back to the tank.

 

[AMcCormick]

try checking the inside of the pump for debris, on the aft side of the pump is a cover plate with four allen head fasteners.

 

[BIGNASTY]

Air dog return

Had my truck running a while back and took the fuel cap off, noticed that there wasnt any fuel going through the return line back into the filler neck. Usually there is a large amount of fuel going through the return line from the air dog to the filler neck. If the truck is running or I bump the starter I still show 16-18 psi. I have called pure flow several times in the last month and STILL no call back with an answer. Any thoughts?

After reading your post I went out and just turned on the key got fuel return.

Then started motor and still had return to tank my pressure is 16 psi

 

[MVieira]

DHayden, Something doesn't sound right. The AirDog return line tube, that splices into the filler neck hose, is pretty close to the fuel tank. It is quite a ways down the fill hose. This is on my 2002 with the install kit I got with the older FP80. I can't actually see the fuel returning in the filler neck, it is too far down to see, but you can hear the fuel return with the cap off and the engine idling. Not trying to insult you but are you looking at the factory vent line near the top of the filler neck ?
Regards, Mike.