Yea I will have to check around but I will need to find some fittings as mentioned and some ether hose.. Could I just get another draw straw and some of that ether tubing instead of that fitting?

 

Nice documentation man! We have been doing them pretty much the same way for a while, but still occasionally had that fluctuation...Just figured out I would start plumbing the return back into the basket also. Glad to see I am on the right track!!

 

**Small update**
thanks for the comments guys,
I am really happy with the way this mod has worked so far...the only problem I had was the grommet on the return line was kinda a loose fit so when I filled up it leaked.....the grommet does not fit perfect because the plastic on the tank is thicker then the canister plastic so...YOU HAVE TO DRILL IT UNDER SIZED or it will leak..one hole I drilled was undersized (AD suction/pick-up) the grommet on that one did not leak because it was tight...but the return line did..
I had to use some Super duty marine permanent sealer on the grommet...but this can all be avoided if you under size the hole!!!!!!!

 

What size fuel tank do you have??? I currently have a 35gal tank and am running out of fuel when at 1/4 tank while going down hill. The hill is approx. 8-10% grade for 300ft, and by the time I hit the bottom I am out of fuel and truck sputters and dies. We did do the mod as you re-wrote with plumbing the return into the canister from the filler neck. This solved by fluctuation under normal 1/4 tank conditions, but when i leave my house to go down the hill I run out.

I am wondering if you have the 26 or 35gal tank? With the 26er, the fuel does not have as far to go when going down hill but with my 35er it ahs further to go and thus empties the basket.....


Anyone have any thoughts????

Currently my DTE says 180mi and going down hill I run the pump dry!!!!!

 

Wow man that sucks.....When you say "We did do the mod as you re-wrote with plumbing the return into the canister from the filler neck" does that mean you have the return line plumbed directly into the canister top?? I have a hill by my moms house that is steep and longer then 300ft and I was only able to get my fuel psi reading to drop to 8psi and that was only for s half second...I thought the tank sizes are 30g on the megas and SB and 34-35 on the LBs???I dont think the tank size is the problem....but you never know? I would wonder if you cut the pick-up to short??? did you use flexible hose for the pick-up?? and did you use hard line on the AD return line so it was sure to fall in the basket???it took me a lot of test fitting to make sure my pick-up was perfect...I also cut a "V" on each side of the pick-up to make sure it did not get closed off.I would have to see your set-up to know for sure....is it exactly like mine or is is similar except you did "x" different??

 

We did not use the Vulcan "Draw Straw" as you have, we used the supplied AD 1/2" straw but it was cut as close to the bottom as possible. The return line is hard lined from the fitting on top into the canister and we modified it by putting a cap on the end of the PVC, but we drilled holes in the pipe and cap to shoot the return fuel to the sides of the canister to allow it to flow down the sides of the canister to aid in de-foaming the fuel.
My truck has a 35gal tank and I have a QC short bed.

I, we, are at a loss for why this is happening??? As I said before under normal driving the psi is solid, only when I hit the binders extremely hard does the psi move, but it only drops a few psi. But with this it actually died this morning!!!!

Is it possible that the AD150 just pulls too much fuel and that the canister even with extra holes in it just can't keep up???? I know with my stock pump I could run the fuel all the way down to when the light comes on and still have 7-9psi while going down this same hill. Could it be that the difference in flow ratings is what is causing this????

 

maybe you are not allowing enough fuel to flow back to the canister with that cap and holes drilled in it??if you did not use any flexible line on your pick-up I can almost guarantee that is why...I think it would be dang near impossible to cut it at the right length with a solid line...I know the AD150 can drain a stock basket in no time!! Charlie told me that a long time ago...that is why I used the AD return line to "refill" the basket.my megacab tank is 34 gallons I just looked it up.all I know is my FP is more solid then it ever was with the other set-up..it must be some thing you did different on your install vs mine???

 

one more thought.....when you use a solid pick-up with this mod you are spacing the straw farther then you think from the bottom of the tank...between the screen on the bottom of the canister and the second solid plastic bottom above that and already make a big gap between the bottom of the tank and the pick-up..that is why you have to use flexible hose and kinda "smash" it on to the bottom of the canister...with out restricting flow...its kinda tricky!!

 

We did the math and the total volume of the holes we drilled is greater than the volume that the return sends back...The pick-up is flexible tubing.

Once the FP drops below 15psi the return line is no longer active due to the by-pass closed, so when I go down the hill and my relief valve is not open due to low psi, then there is no fuel going back into the basket to refill it.....

 

I dont know what to tell you man...mine works great!!!!!!!!

maybe your hill is way steeper then my test hill?? but even then I wounder cause I sat on the hill for a while to see if I could stall it or get a 0 psi reading...never got below 8psi.....</p>

 

What do you mean you did the math? Based on what?

I don't get the second part, in order for your FP to drop below 15 PSI would mean you have your foot to the floor, all the fuel the AD puts out is going to your engine, and this is while going down hill? How fast are you going at the bottom?

 

The math we did, was take the total volume @given psi going through a 1/2" line and make sure that the total # of holes and their volume was equal to or greater than the volume of the line...

The second part is if I am going down my hill @ 5mph with 1/4 of a tank of fuel, all the fuel goes toward the front of the tank and uncovers/drains the basket of the pick-up. When the pick-up is submersed in fuel the by-pass opens up @17-19psi to relive the psi going to the CP3. When this pick-up becomes starved for fuel the by-pass does not open to relieve psi. It stays closed because there is no fuel present to return to the basket via return line.
When this happens, no matter how much fuel should be going into the return is not.

Thought about it today and we might put in a second pick-up in the front of the tank, so that when I go down my hill and all the fuel sloshes to the front of the tank it will still be picked up by the second draw straw....


Some people might think of this as overkill, but as I said before I live on a STEEP hill, and when I can starve my pump for fuel with 3/8 of a tank going down this hill it is not good....

Other than this little problem, my fuel psi is solid all the way down to 1/8 of a tank, so Mark your methood does work and works well...!!!! It is just that I have a very unique situation.

Thanks for all your help!!!

 

Okay, I get ya.
Too bad the tank weren't see through so we could actually see what's going on in there eh?
Let us know how it goes...



<EDIT>

Mark, is there anyway to keep the factory pump setup to keep drawing fuel into the canister as well as running the AD draw and return lines to the canister?
Maybe reducing the voltage to the factory pump so it flows less, but with no fuel going to the engine it probly wouldn't need to flow much, lengthening it's life in the process?

 

Will do....

 

if you want to run a second pick up you will need some sort of check valve..other wise the second straw will suck air when you go up the same hill...the check valve would have to be able to tell the difference between air and fuel too?