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Discussion Starter #1
Ok, I just installed an Airdog 100. I had issues getting it installed at a 1/2 tank of fuel. I filled up the tank, and it worked fine. I drove the truck for a couple of days, got down to a half tank, and started losing fuel pressure. So I filled the tank up, and now keeps fuel pressure, about 13-15 psi. So basically I'm asking, where could I be sucking air. Is the sending unit bad, maybe a hole in the suction line. I'm not sure.
 

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Senior Member
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I found out the hard way that my sending unit was bad. It took out vp44 when it ran out. VP was probably on its way out anyway.
 

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2nd Gen Guru
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Ok, I just installed an Airdog 100. I had issues getting it installed at a 1/2 tank of fuel. I filled up the tank, and it worked fine. I drove the truck for a couple of days, got down to a half tank, and started losing fuel pressure. So I filled the tank up, and now keeps fuel pressure, about 13-15 psi. So basically I'm asking, where could I be sucking air. Is the sending unit bad, maybe a hole in the suction line. I'm not sure.
Your hooked to the stock sender correct?

I found out the hard way that my sending unit was bad. It took out vp44 when it ran out. VP was probably on its way out anyway.
Yeah I had the samething happen with me... Just after my AD 150 was installed my fuel sender went out. But now I've got it replaced and it works fine... Dropping the fuel tank isn't hard I got it done in about 1 hour from start to finsh. The sender can be purchased at a dealer for about
$70 bucks. Quick and easy to do...
 

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Discussion Starter #4
correct, it's the stock sender. I think there might be a hole in the draw straw. At least that's the only reason I can think that I couldn't pick up fuel just when I'm below half tank.
 

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2nd Gen Guru
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Possible... But while your there inspecting your pickup assembly I would inspect the fuel gauge sender too... So no matter what you going to be dropping the tank...
 

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when you fuel up below the half tank how much fuel you adding? That will give you a good gauge on how well the gauge is working.
 

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Discussion Starter #7
I'm putting in about 18 gallons @ a little above a half a tank. (It's not the stock tank) But I'm not having problems with the the fuel gauge, just the fuel pump.
 

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********* and Mafia #90
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my fp150 will start to suck air around 1/4-1/8 tank.
 

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Yeah with my drawstraw I can hit the 1/8 of tank LOW FUEL light before sucking air...



Not unless I'm being stupid and getting on it on a steep dirt road I can suck at 1/4 tank but I really got to be doing something stupid...
 

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Discussion Starter #10
The thing that I can't understand is with the stock LP, I could run it even after the low fuel light was on, and now I can't even make a half tank. :bang:
I'll let you guys know how it turns out.
 

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where did you put the return off of the pump? I had this problem with a 150 air dog and had the return into the filler neck. The pump flows enough it will suck the sump dry and get air. When we put the return back into the sump no more problems. It cost me a vp to find this out.
 

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where did you put the return off of the pump? I had this problem with a 150 air dog and had the return into the filler neck. The pump flows enough it will suck the sump dry and get air. When we put the return back into the sump no more problems. It cost me a vp to find this out.
I would love to see your setup...

Mine also is in the filler neck and I've managed to get down to 1/8 tank with much problems... I rteally don't want to burn up a VP44 though...
 

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Heavy Equip. Is My Life
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The sender can be purchased at a dealer for about $70 bucks. Quick and easy to do...
Mike, I tried ordering one from the dealer and they told me the only thing available was the updated unit with the in-tank pump. Will a '98 one fit or what's the trick to getting an old style unit? Russ
 

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Now that looks like a good draw straw setup...:thumbsup
 
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********* and Mafia #90
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wheres the return fuel go? does it get sprayed into the tank or right back into the pick up tube?
 

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wheres the return fuel go? does it get sprayed into the tank or right back into the pick up tube?
According to Vulcan Perf. the return fuel runs down the outside of the draw straw...
 
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What are sparkplugs
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I had same problem with the fass the draw straw would start sucking between 1/2 and 1/4 tank, I went to dealer they had a couple of old sending units(no pump) for 35 bucks I installed that run fass through that "pickup and return", now I can use about 28-29 gallons with fuel gauge almost touching "E" before it starts sucking.
 

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Discussion Starter #20
Ok, this Vulcan draw straw looks like something that could alleviate my issues. Now what would you guys recommend for the Airdog 100? 1/2 or 3/8 and flexible or rigid?
 
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