ok after changing all the fittings on my airdog, sending the pump to airdog, and changing the fuel pressure sender just to make sure i still have low fuel pressure at the bowl. the airdog checked out good. i run at 50 psi but as soon as i give it fuel it drops to 40 psi, which i know is not good. the last thing i can think of is the o rings on the injectors. any more thoughts. i cant do the blue spring because of the rr.

 

Can you set your initial pressure to 60? Or maybe your rr is malfuntioning. Its a normal function of hydralics to lose pressure when a valve is opened. Isn't 50 psi still a little low or too close to the mark for me at least.

 

Have you tried taking the fuel pressure reading from the regulator instead of at the fuel bowl to see what kind of drop you get? Balancing the RR and the AD is a real trick. Maxing pressure out at the pump may be causing a loss of flow. Try backing the pressure screw out 1/2 a turn and raise the pressure with the RR to see if it changes.

 

is there any kind of filter on the fuel intake in the fuel tank that could be restricting the volume of fuel to the pump itself. hook the pump up to 12 volt direct and time how long it takes to fill a 5 gal bucket. then put the pump suction line in the bucket and see how fast it pumps it with no intake restriction.

 

I can't set my pressure at all. The airdog won't adjust. I talked to Itp and they said to close the regulator and then adjust pressure but I did that and nothing happend. Airdog said the pump was fine though

 

how much restriction is at the suction side of the pump?

 

im sucking at the draw straw. not sure that there is any restriction. ive had this problem for a few months. everything was fine a few months ago and then boom all of a sudden my dad took my truck for a week got it back and now cant get the fuel pressure to go back to where it use to be. my dad didnt do anything to it. he babied the truck and just drove it around the job site. i really am stumped. maybe the regulator is bad but it has a mechanical screw to adjust it so i wouldnt think that it could go bad.

 

any ideas?

 

if the pump has checked out, i can only see three other things, in no particular order. 1 poor electrical connection on pump can't get enough volts to keep up(long shot) 2 restricted suction, 3 bad regulator flowing too much fuel(pump is running at max flow just to hold idle pressure)

 

see i thought about the voltage deal too. im thinkin your right on one of the three or maybe all three. i know its possible but is it likely for a itp regulator to go out? also is there a quick way to make sure nothing is in the draw straw? i know the line is free and clear just not sure about the straw

 

So if I am not mistaken, you have ITP's regualted return and the ADII?

 

actually i have heard of some issues with a plug on the side of the straw falling out and causing issues when the tank is less than 3/4 full. that typically puts a ton of air into the system although the air dog might clean that up and just reduce the flow rate

 

To prove the regulator you can gently pinch it's return line with a pair of vice grips or clamp while you watch the pressure.

Did you install a new pickup tube into your fuel tank? The stock tube has a screen on the bottom. You can use low pressure compressed air to blow back from the pump to tank if you think it's obstructed.

 

Is the pick-up tube filter replaceable I would drop the tank and check the p/u filter

 

yea i have an airdog II and the regulated return. im going to try to pinch the line when i get it back thursday and see what that does. so if i take compressed air and blow the tube out will that clear it?