I have an airdog 2 165gph going to a regulated fuel return. When I start if lt goes to 45 then 55 then 60psi then just drops to 45 I tryed to find a leak no luck. When I turn down the pump it just can drop to zero

 

What kind of regulated return do you have? Balancing the regulated return with the ADII can be a bit of a trick.

 

Sinister diesel

 

Here's the way I set mine:

1) Turn the PUMP regulator all the way in and back it out about 3/4 turn. DO NOT tighten it down when turning it in. All it has to do is lightly touch the seat.

2) Adjust the fuel pressure regulator under the hood to 58 psi.

If you're having issues with the pressure not staying adjusted then using the AD2 instructions remove the fuel pressure regulator adjusting screw and the plunger/piston and check the small o-ring on the end. I'll bet it's split/broken. The pump comes with a spare one. Replace, install, and retest. You may have to adjust the fuel pressure screw a bit but remember that more pressure does NOT equal more fuel. It's more important to maintain the fuel pressure steady at 58 or 60 than have it at 70 and drop to 45 or 50 at WOT.

 

I just read a thread about this particular part failure on the AD2. If you can get a Viton O-ring sized a011 to replace it you'll be better off. Harbor freight carries a kit with several sizes for a very good price. ~$10

 

Well **** I cleaned the pump and now I have no fuel pressure

 

I need a good lift pump?

 

Cummins need lift pumps...

Josh

 

Fuel pump thing thst pumps fuel lol

 

What's wrong with the stock HFCM?

Josh

 

Haha my thoughts exactly.

 

You may need to loosen the water separator and key it on to get it to prime.

 

Doesn’t pump any fuel to the motor

 

So you have an AD2 feeding your stock pump??

 

No no airdog is just messed up and the stoxk before it messed