This thread is where I will post updates of my modifications, issues i've had, and potential upgrades I'm considering.  

 

This page is dedicated to @TFaoro, because without him my truck would be bone stock still....

 

To start off, today my VP died.  It took me by surprise, as it gave no indication there was an issue.  But, it threw Death Code P1691, and that's that.  Good thing it died before I bought tires.

 

Is DAP everyone's first choice for a new VP?

 

Edited March 15, 20178 yr by trreed

2 hours ago, Dieselfuture said:

What I found out is diesel fuel foms a lot, which should have been clear to me after watching it foam when you fill up a 5-gallon can at the pump. See if the cavitation goes away with full tank versus quarter of a tank. Otherwise air is getting entrained one way or the other. Also could just be ball and spring in the return side of fass if you're experiencing pressure swing. 

5

 

This is one reason I love my old school draw straw (without the basket). My return is the filler neck so the foam issue doesn't occur. Never have this issue at all. Still, to this day don't have any quarter tank issues either with a 12 year old AirDog 150.

Edited June 16, 20177 yr by Mopar1973Man

39 minutes ago, Mopar1973Man said:

 

This is one reason I love my old school draw straw (without the basket). My return is the filler neck so the foam issue doesn't occur. Never have this issue at all. Still, to this day don't have any quarter tank issues either with a 12 year old AirDog 150.

So how do you have the fuel tank level sending unit mounted without the basket? Or am I missing something?

@JAG1 he left his basket alone and his return from head and injectors still return to basket, when unmolested it goes all the way to the bottom. And his ad 150 returns to filler neck. Difference is Mike did it himself right the first time so the straw is at the bottom. I and many others that suffered from 1/4 to 3rd full tank sucking air issue when stopping or taking off quick, ended up modifing fuel basket and not everyone did that one right ether. In my case po did the draw straw install and when I decided to modify basket I realized that my straw was at least an inch from the bottom, so instead of ordering another straw I did the basket upgrade since I had the kit in the garage. 

So my draw straw is about 1/8" off the bottom of the basket, so the cavitation issues caused by foaming shouldn't be an issue.  I'm thinking its either the water separator filter (which I'll be replacing tomorrow) or the ball and spring, and i've already messed with that.  Who knows though.

 

It's not so much the draw straw that will cause cavitation but the return lines if they go to same place. Draw straw if installed wrong will cause sucking air when fuel gets low, but if it's installed  in your basket and return fuel also goes to basket you have to make sure return is as low as the draw straw or it will foam fuel that draw straw is trying to suck. 

My pick up and both return lines go into the basket. I have had no issue with any cavitation or premature fuel starvation. All part of the kit that came with my AD. It will also suck the tank dry.  I have, however, always wondered how warm the fuel is with this set up. 

I have a pre filter that tends to hold an air pocket above the filter in the filter head. It keeps building air in there coming in from the draw straw. I bleed it off and it develops again. So last night a plumber friend of mine made me a filler neck piece with a half inch 'T' so I can plumb in the return to the fill neck.

 

If this doesn't stop the air the next thing will be to cut off the quick connect at the draw straw and hose clamp it in place.

 

Todays project anyway

Edited June 17, 20177 yr by JAG1

Sounds like we're both gonna be having fun with fuel today. 

Good news!  I replaced the water separator today, and the new filter eliminated 97% of my cavitation issues. So guess I got a bad filter last time. 

Nice! I should replace mine to see if I just got junkers from FASS!

I got the fuel return going into the fill neck.. I will know in about a day if that solves the remaining 10-20% of the F/P gauge fluctuation. Used to be all over the place when first installed and I think an indication of air and/or cavitation problems.

 

 

On 6/16/2017 at 8:40 AM, JAG1 said:

So how do you have the fuel tank level sending unit mounted without the basket? Or am I missing something?

 

Stock basket is still present untouched. Draw straw is not inside nor near the stock basket. My straw is in the open space of the tank without any reservoir or basket. Return line from the engine is still fed to the stock fuel basket. My AirDog return is in the filler neck away from the draw straw. My straw tip is only the thickness of a single quarter (coin) to the bottom. I've gone several times well below the 1/8 of tank and touched empty a few times without much issues.

Edited June 18, 20177 yr by Mopar1973Man

Had a question.  A while back, someone was talking about return springs from Vulcan (I think it was @dripley?) and ordering the 17 psi return spring.  I don't see any spring labeled FASS on their website, does anyone know if they stopped carrying the FASS springs?  Or is there a hidden spring I'm missing on the site?

It's because it's not a FASS spring, it's an Airdog spring!

 

http://www.vulcanperformance.com/Spring-AirDog-17-PSI-p/1v-1-00003.htm

 

and it was probably me talking about it lol. Might also be worth buying the Viton ball the Airdog system uses as well, it's a little tougher material and seems less prone to get indented by the spring.

 

Edited June 19, 20177 yr by notlimah

I'm glad someone caught the hidden question!  It felt pretty dumb to ask "does the airdog spring fit in a fass?"  Maybe I've been spending too much time in the Facebook groups reading "how much tire can I fit with no lift".....

 

@notlimah did you stretch the spring out at all to up the pressure or just run it as it?

 

As for the Viton ball, that is a good idea. My original one definitely has scoring from the spring on it. Hopefully this combo will stop my fluctuations in the FP gauge

2 hours ago, trreed said:

Had a question.  A while back, someone was talking about return springs from Vulcan (I think it was @dripley?) and ordering the 17 psi return spring.  I don't see any spring labeled FASS on their website, does anyone know if they stopped carrying the FASS springs?  Or is there a hidden spring I'm missing on the site?

Not me. Glad you seemed to have found the right person though. One of the reasons I bought the ADII was that it has a regulator that I can adjust. 

Honestly, with all the issues I've had with keeping consistent pressure, I've thought about removing the ball and spring completely and putting an adjustable regulator in the return line..

Edited June 19, 20177 yr by trreed

I didn't stretch the spring, just ran as is and haven't seen pressures below 17 when driving once warmed up.

 

The viton ball does make a difference imo.

 

Here's what the (3rd) Buna ball from FASS looked like when I took it out and was having issues with erratic pressures

 

 

It's the closer one in the shot and you can see the clear indent.

 

It was stuck in the spring and caused the spring to even collapse on itself like this

 

 

This is also caused my fuel pressure to increase with rpm. 

 

I think youll notice things smooth out once the airs out airs out of the system with the new spring and Viton ball. You can't use the Airdog return line fitting though. It's too big.

 

 

Hard to tell by that pic but it won't seat all the way so just use your FASS fitting and Airdog spring and ball.

 

also fwiw, if what I just posted didn't work for me I was looking into the regulator as well. Just a tough one to swallow spending 140 on top of the 600 dollar price tag 

My fass ball looks an awful lot like yours does, and I was also noticing spikes in pressure at higher RPM..  So the new spring and ball are now on their way (along with some new hose for good measure) and hopefully that'll fix some of these issues.

I'm sure glad someone else has had these issues!

 

I'd it this mod to my spring to air dog when I had it and now to fass and it keeps ball from getting jammed in a spring and seems to keep pressure steady