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Draw Straw 2 Whole Inches Off The Bottom......


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I think this is the cause of the AD 100 giving off this sudden intermitant whoot like sound as if air is shootin' thru. Those moments show a very quick drop in Fuel pressure.

 

Could it do this even at a half a tank though?

 

Just wonderin' what your thoughts might be.... I can't just extend it with a piece of hose and clamp. It will cause a hang up with the lower sleeve of the module extending and retracting  :popcorn:

Edited by JAG1
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it's never done it  with a full tank?  (major hint)     is this  when  you are  sitting or  moving?

 

have you ever seen  a  suction  hose  in  any  liquid>   it  tends  to create  a  vortex/whirlpool effect.     The  shallower  it is,  the  easier it is to  pull air.   

 

Pretty sure  you  can't  hear  the whoosh  when you are driving, but  sure can 'see' it  in the gauge.    but    I'd  bet  when   you are   accel-deccel,    fuel is     getting pretty  shallow  at times  over the   straw too.

 

How did the   straw  get so high  from the  bottom?   Is that  what's  recommended?      

 

sitting here,  I can't  visualize  the  location of the   filler  neck,  and  the   pickup tube.    I've wondered  if the  foamy return is  getting dumped  right on top of the   straw.    The  AD   demonstration   video   shows  quite the   blizzard  of  air and  fuel  going back through  return.     Is  it  cold enough  to  thicken the fuel  enough... so the  tiny bubbles   can't  rise  before getting  sucked up again?

Edited by rancherman
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rancherman thank you for the thoughts. That is one intelligent post you made. Thank you.

 

Yes it occurs at half a tank. Used to only see it at a quarter tank but since I was in Nevada where it's much colder, like you say, the fuel is much thicker.  It happens when running and sloshing the tank on turns, braking and take offs.

 

Now how it got so short......... never knew it was till yesterday, been at least 7 yrs like that since I trusted the guy that installed it. No, I'm not one to blame someone since I've made more mistakes with age.

 

Should I order a new draw straw and cut it about 1/2'' off the bottom at an angle? Or should I just add a piece of clamped on rubber hose up higher? With the hose higher it won't be hitting, interfering the sleeve action of the module. I'm worried the rubber hose will cause other issues later down the road.

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Mopar Mike, I like the pic you posted above.

 

It shows your draw straw but no module/ anti slosh tube around it. Is it installed that way? With that part of the module gone or removed?

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Mopar Mike, I like the pic you posted above.

 

It shows your draw straw but no module/ anti slosh tube around it. Is it installed that way? With that part of the module gone or removed?

 

That's all I got is the straw. This is how the old school AirDog pump were sold back in the day. But I don't need a anti-slosh basket. I've been know to drive all the way down to Empty mark without much problems. Then I've pumped out my tank a few times for repairs and the straw pumps every last bit from the tank there is less than a quart of fuel left. But I know there is no way to do that with the truck moving.

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I'd  say yes,  to  your  fuel pressure drop  from  full to  pert near  empty.    (the more  'foam'  you are sucking,   the less  pressure  overall)   and   with  the   straw   2 inches  off the bottom,    you are definitely   in  the   'foam'.  LOL 

plus,  you are  correct on the   hydraulic  scenario..   your pump  has more 'head',  and it's  efficiency is  lower.

 

I'd sure  cut it  at  a slight  angle,   just   for    'one less thing to  happen'.. ie:     bottom of  tank  getting  sucked up  and   attaching itself to  drawstraw.      (whether it's    pushed up  from    something  you  rubbed,   or    have  a little  too much  vacuum  and  it's  really hot..  flexi-tank)

 

I  don't  think  you would  need  a  45*  angle,    maybe  half?

Edited by rancherman
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http://www.cumminsforum.com/forum/94-98-engine/8792-vulcan-draw-straw-installation.html

 

If you have discarded the strainer basket, you may want to fix the two halves of the module together, so they don’t move and affect the fuel level sensor. The measurement for this should be done taking into consideration that the strainer basket rested on the base of the tank. Use a couple of self-tapping screws to accomplish this.

 

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Is your draw straw installed IN the strainer basket of the original pickup?  Does the AD return also go into the basket?  The AD will draw more than the OEM strainer will flow if the return is outside the basket & can lead to drawing air even with fuel in the tank.  Either both in or both out or pop the screens out of the basket.

 

Another common error is measuring the tank for the draw straw with the tank sitting on the floor.  The bottom of the tank will deflect resulting in a bad measurement, a wrong cut on the draw straw & drawing air with fuel in the tank. 

 

The recent draw straw quick connect fittings have been problematic...  failing & drawing air.   Likewise there can be suction line failures...  rusted out lines for instance.   Unfortunately it requires accessing the tank.  

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My ADII came with a  kit to remove the in tank pump. It also placed both return lines into the fuel basket with the pick up. I know I cut my pick up line a touch to short and also cut it on about a 15* angle. I worried bout it at first, but it will suck the tank dry. I have put 35 gallons in it on a couple of occasions. 

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I like all your ideas and discussion about this. Seems I don't even need the module to slide up and down. It can be made stationary with some screws. The plastic is rather brittle so I would pre-drill for any screws to be added to insure you don't crack the module.

 

 I could remove the bottom most piece (just snaps on) that used to hold the fine screen mesh on the sides, which were cut out years ago. This would allow for a 1/2'' hose clamped on to extend closer the bottom and not get hung up with movement.

 

Cool! Thanks you guys.

Edited by JAG1
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This where you buy the beer, find a friend to drink beer with and then get him to do the fuel tank while you continue to drink beer and shoot pictures of him doing the work. Lot easier than mod'ing the truck bed. :lmao2::lmao:
 
 
 
12 seconds with the cordless drill and my fuel tank top is exposed :tongue: .
 
 It took 2 and 1/2 days and every bit of head ache to figure out how to do it.  Believe me..... it ain't worth it..... unless you like a real challenge. I like doing the impossible sometimes... it gets me goin.
 
Okay...... last night I modded that canister, cut the bottom off to get the bigger hose thru, ran the screws to make it solid, (no more slide extension) and added 1 3/4 inches to the draw straw.
 
I hope it stops the 0216 code I've been driving on for two years from pulling air with a short drawstraw.
 
I'm sorry for no pics yet. I do not know how and the wife has been busy with tax season starting. Should get them up today.
Edited by JAG1
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