So I finally ago around to installing the T fitting in my fuel line after installing the AirDog 100 about 4 months ago so that I can monitor the fuel pressure and it reads 2-3 psi.

I'm not sure if it is the gauge or the pump. I replaced the fuel filter and there is no change. I get 3psi steady and can't draw it down, but its not what I expected to see at all.

I'm running a dipricol mechanical fuel gauge with an isolator and antifreeze up into the cab.

I'm going to clean the electrical connections to the battery and use some dielectric grease (looking a little corroded).

What are the other things that I need to double check or try to get the proper pressure out of this fuel system?

 

Give the AirDog manufacturer a call at 877-463-4373. I do not know what the 100 is to flow, but my SuperDog 250 pushes a steady 11 psi on a 1/2" fuel feed line at all throttle positions on my very pumped 5.9. I have only tested mine to 100 GPH as that is the limit of my FloScan, and it never has varied.

The AirDog has an internal bypass that limits pressure to the injection pump, and they rely on volume of clean fuel presented instead of just pressure.

 

Your problem MOST LIKELY is your isolator, try a pressure test without it probably have 10-23psi mine runs 24psi Ed

 

Ditch the isolator and install a needle valve. If your line or gauge breaks you won't get more than a drip out of the line with a needle valve in place. My airdog makes 22 pounds of pressure but I have a stronger spring in it. The stock spring made 17 pounds and would not pull down any either.

 

You guys hit the nail on the head.

I re-bled the whole fuel system and no change.
Checked the electrical connections and no change.
Bled the isolator and refilled the antifreeeze and I'm reading 15 psi now at idle and WOT. I'll look into the parts required to remove the isolator soon.