Suction tube or sump kit

[Mar25]

I already have the fass titanium 150 but when my truck reaches half a tank it starts acting unlike most post are about the 1/4 tank issue mine is the 1/2 tank issue. I have noticed that with a full tank I get 16 psi on my fuel gauge but once it's half a tank it ranges from 15-21 psi which I have been told that u either need a needle valve or a snubber due to not having either or which is that correct? And would the sump kit or suction tube help my 1/2 tank issue

thanks 

[Me78569]

When you put the fass in what lift pump did your truck have?  Was it on the block or in the tank?  

 

You should always have a needle valve or snubber before your fuel pressure gauge.  

 

Your issue is weird though,  Have you opened up the tank cover yet to see what's in the tank now?

[Mopar1973Man]

Sound like someone cut the tube too short. Another thing I see is people cutting weird angle cuts on the tip which causes this too. Straight cut and it should be the thickness of a quarter (coin) from the tip to the bottom of the tank on a empty tank. As the tank fills the bottom deflects away from the tip (about 6 pound per gallon).

[98whitelightnin]

I really wish I had gone with the draw straw instead of sump but after all the horror stories with 1/4 tank issues with the straw and nothing on the sump, I went sump. When mine gets to 1/4 tank, it looses fuel pressure and won't hardly run with this Beans sump drilled directly below the stock pickup.

[dripley]

4 hours ago, Mar25 said:

I already have the fass titanium 150 but when my truck reaches half a tank it starts acting unlike most post are about the 1/4 tank issue mine is the 1/2 tank issue. I have noticed that with a full tank I get 16 psi on my fuel gauge but once it's half a tank it ranges from 15-21 psi which I have been told that u either need a needle valve or a snubber due to not having either or which is that correct? And would the sump kit or suction tube help my 1/2 tank issue

thanks 

i agree with Me that you need to open up the fuel tank and see what you really have, unless you did the install then you would already know. Just about all the 1/4 tank issues I have read of involve loss of fuel due to the straw being cut to short and with that a loss in pressure. Pressure fluctuations like you are seeing are usually caused by the hammer effect from the pump, but you would see that thru the entire tank and not just the last half.

if you off road alot I could see the sump being a problem with possibly getting knocked off. Pavement queen maybe not. Mine is 97% pavement queen, but I chose to have my pickup in the fuel basket and it works as well as the oe setup. i do however run a needle valve to protect the gauge after beating my first one to death. Both of mine are and were mechanical.

[Mopar1973Man]

This picture will look like the tip is touching the bottom of the tank but it not. There is a gap the thickness of a quarter coin between the tip and the tank bottom. As for the tip you'll see I lightly notched the tip with a grinder disc so it can hold suction to the bottom. The fuel in the picture is just a quart. As you can see it still covering the tip but this is the only bit of fuel the AirDog 150 couldn't pick up.

Edited November 11, 2015 by Mopar1973Man

[Mar25]

2 hours ago, Me78569 said:

When you put the fass in what lift pump did your truck have?  Was it on the block or in the tank?  

 

You should always have a needle valve or snubber before your fuel pressure gauge.  

 

Your issue is weird though,  Have you opened up the tank cover yet to see what's in the tank now?

I have the intank I believe due to me having to run line to top of tank.

would I need a new sensor since I haven't put a snubber on.

i have never looked inside the tank

4 hours ago, Mopar1973Man said:

Sound like someone cut the tube too short. Another thing I see is people cutting weird angle cuts on the tip which causes this too. Straight cut and it should be the thickness of a quarter (coin) from the tip to the bottom of the tank on a empty tank. As the tank fills the bottom deflects away from the tip (about 6 pound per gallon).

Which tube to short?

[dripley]

If you installed a Fass system and just connected to the top of the tank and have the in tank pump you are trying to pull fuel thru both??? Where do you get power for the Fass? 

[Me78569]

Did you remove any lift pump when you put the fass on?   Dripley and I are thinking the same thing.

[Mar25]

13 minutes ago, dripley said:

If you installed a Fass system and just connected to the top of the tank and have the in tank pump you are trying to pull fuel thru both??? Where do you get power for the Fass? 

What do u mean by pulling threw both? I removed the factory line from the top of the tank as the fass directions said to do and connected the new 1/2inch line to the top of tank. And the fass is connected to the wiring provided by it and I disconnected the lines from the fuel filter on the block 

15 minutes ago, Me78569 said:

Did you remove any lift pump when you put the fass on?   Dripley and I are thinking the same thing.

I have not removed any left pump when I installed fass

[Me78569]

With our trucks there is a OEM lif tpump either on the side of the block by the oem fuel filter, or there is an OEM lift pump in the fuel tank.

 

Did you fun the fass lines to the oem fuel filter or right to the vp44 injection pump?  

 

What he means by pulling through, is you have your fass trying to suck fuel through the none working OEM pump in the tank.  this will cause issues such as low pressure and prob the issues you are seeing as the FASS pump is sucking fuel through the other pump.  

 

Take a straw as an example, if you just suck through a straw into a glass of water, it sucks easily, HOWEVER if you cover the end of the straw in cloth then try to suck through it is be much hard to do.  

Edited November 11, 2015 by Me78569

[dripley]

if you do have an intank pump and just connected to the top of the tank then you are pulling fuel thru the in tank pump. If you powered the new pump from wires you say you removed from the fuel filter, there are none on the filter but are on the oe block mounted lift pump just aft of the filter. 

I have an Air Dog on mine and if I am not mistaken they install very similar. My truck had the aftermarket Dodge in tank lift pump that replaced the block mounted pump. I am think from your description that you have the oe block mounted pump but not sure. My AD also came with a kit to remove the in tank pump. If you look just aft of the filter is there a pump mounted on the block?

[Mar25]

1 hour ago, Me78569 said:

With our trucks there is a OEM lif tpump either on the side of the block by the oem fuel filter, or there is an OEM lift pump in the fuel tank.

 

Did you fun the fass lines to the oem fuel filter or right to the vp44 injection pump?  

 

What he means by pulling through, is you have your fass trying to suck fuel through the none working OEM pump in the tank.  this will cause issues such as low pressure and prob the issues you are seeing as the FASS pump is sucking fuel through the other pump.  

 

Take a straw as an example, if you just suck through a straw into a glass of water, it sucks easily, HOWEVER if you cover the end of the straw in cloth then try to suck through it is be much hard to do.  

I ran my lines straight to the vp44

i honestly don't know I have tried getting an answer from other people but haven't I've always been worried I did something wrong but the fass and new vp44 have been on for 6 months now 

58 minutes ago, dripley said:

if you do have an intank pump and just connected to the top of the tank then you are pulling fuel thru the in tank pump. If you powered the new pump from wires you say you removed from the fuel filter, there are none on the filter but are on the oe block mounted lift pump just aft of the filter. 

I have an Air Dog on mine and if I am not mistaken they install very similar. My truck had the aftermarket Dodge in tank lift pump that replaced the block mounted pump. I am think from your description that you have the oe block mounted pump but not sure. My AD also came with a kit to remove the in tank pump. If you look just aft of the filter is there a pump mounted on the block?

Is there any good pictures to see what the pump on block and in tank look like? My fass did not come with a kit to remove it 

[Me78569]

number 15 below and behind the fuel filter.  

 

 

 

Tank

 

The bendy straw on the right leads down to the in tank pump

Edited November 11, 2015 by Me78569

[Mar25]

4 minutes ago, Me78569 said:

number 15 below and behind the fuel filter.  

 

 

 

Tank

 

The bendy straw on the right leads down to the in tank pump

I will have to go outside really quick to truck but I do remember the line that is the suction from the fass is connected to the similar top of the intake pump

[Me78569]

I would look at the block location first, if you don't have a pump on the side of the block then one is in the tank.  

 

I beleive the top of the fuel tank canister is the same regardless, so you can't figure out whats in the tank without pulling hte cover.

[BBHD]

My truck had the intank pump conversion. There was an aluminum block inplace of the block mounted pump and a harness with a relay to power the intank pump. Might be easier to check thank pulling the fuel module 

Edited November 11, 2015 by BBHD
Additional info

[Mar25]

13 minutes ago, Me78569 said:

I would look at the block location first, if you don't have a pump on the side of the block then one is in the tank.  

 

I beleive the top of the fuel tank canister is the same regardless, so you can't figure out whats in the tank without pulling hte cover.

I will go look now 

 

[dripley]

here is a picture of my intank pump. The top is different from the one that ME posted, so you may not be able to check just by looking. i am not sure what the top of a stock one looks like. I have to agree with checking the block location first. If nothing is there you most likely have an in tank pump. I ran the in tank pump and a booster pump on the frame rail for about 3 years. Both pumps had there own power source.

Edited November 11, 2015 by dripley

[Mar25]

20 hours ago, Me78569 said:

I would look at the block location first, if you don't have a pump on the side of the block then one is in the tank.  

 

I beleive the top of the fuel tank canister is the same regardless, so you can't figure out whats in the tank without pulling hte cover.

I took a picture this morning sorry for so late post back and so I do have the old lift on side of block and the new wire that u can see is what powers my fass