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 

3 minutes ago, Mopar1973Man said:

That old lift pump and plumbing need to go away if you got a FASS pump on there now.

Is there anything I need to put back as far as removing it or just take it and don't worry about it or the lines 

I think the bracket has to stay. I believe it covers the hole in the block for the mechanical pumps that were on the 12 valves. Mine has something there but I dont remember what. It was put there by dodge when they installed the intank pump. Plus with the intank pump you still needed to use the oe filter canister.

So as far as my issue would the draw straw help my situation or is something not connect correctly 

What needs to be done. All the stock supply plumbing need to be removed. Then a Draw Straw in the tank. Install all 1/2" plumbing with Push-Loc JICs fittings. Then you'll have stable fuel pressure. None of the old stock system should be used or left on the truck really.

Edited November 12, 20159 yr by Mopar1973Man

On 11/10/2015, 7:27:22, 98whitelightnin said:

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.

I'm sad to hear that. I thought sumps were supposed to be the cats meow

7 hours ago, Mopar1973Man said:

What needs to be done. All the stock supply plumbing need to be removed. Then a Draw Straw in the tank. Install all 1/2" plumbing with Push-Loc JICs fittings. Then you'll have stable fuel pressure. None of the old stock system should be used or left on the truck really.

So why a draw straw?  Why do you recommend that people install them?  I don't have on in my truck, what would I have to gain?  Sorry if the questions seems naïve, I have always wondered but never asked.

If you leave the stock pickup you are reducing the flow of the system to whatever 3/8" can flow.  

 

A well installed draw straw works great and gives you 1/2" vs the stock 3/8" 

 

If it ain't broke don't fix it, but if you have pressure issues or 1/4 issues then I would look at a draw straw.

My pick up is in the fuel basket. I used the kit to replace the intank pump that came with my AD. The pickup tube is only 3/8 where the fuel line is 1/2. Plus the connections on top of the basket are slightly smaller than 3/8. In addition I still use the oe filter canister with a Big Line kit from Vulcan performance. So I am 1/2 to the VP with the exception of the choke points where all of the connections are made. I have ditched all of the oe banjo fittings and replaced them AD's and Vulcan's fittings they provided. My FP at idle is 19 and at WOT is 16. My point is unless you are trying to throw some crazy horse power to the ground this works just fine. So to borrow from ME "If it aint broke don't fix it".

Most people buy into the marketing hype that 150 GPH is needed on these motors. Very, very, very few of the builds out there need more than 95 GPH. The bigger pumps can actually be worse as the filters used cannot support the potential flow rate. 

So my point is that the draw straw isn't needed and a modded OEM canister, as shown already, it the best way to avoid the 1/4 tank issues. The return fills the basket as well as the tank fuel which is why you can almost run a OEM setup dry. 

If you are really worried about flow with a 95 GPH pump then mos the canister for 1/2" hose on the auction side and 3/8" hose on the pressure side. 3/8" hose will flow more than enough fuel for just about everyone. 

Just say no to draw straws! 

Edited November 13, 20159 yr by AH64ID

Thanks for the education on the subject.  I have no need for one, I don't have any fuel pressure issues and I can run the tank down pretty low.  I was just wondering what the hoop la was about.

Edited November 13, 20159 yr by Hawkez

Hoop la is marketing mumbo jumbo.  

 

My draw straw is also put inside the oem basket, which as John said returns fuel to.  Very nice setup, but if I didn't have the oem pump in the tank I would have just left the OEM setup.

The only issue with smaller pumps like 95 GPH and 100 GPH you typically see a wider range of pressure change 3-7 PSI. Now a larger pump say 150 GPH which is very stable 1-2 PSI change from idle to WOT. Volume rate of the pump equates to pressure stability.

I knew when I put my AD 165 on it was way overkill. I did however like the pressure adjust screw on it and it came with a kit to do away with the in tank pump. And the cost was almost identical to the 100  and 150 IIRC and they did not have the kit for the in tank pump.

Hard to imagine that the sump would not draw down as far as the tube.

If / when I  change to a larger pump I'll be using the modified liberty module. Makes the install easy and provides plenty of fuel for the pump. It's also just like OEM so absolutely no worries about the 1/4 tank issues.

That said I helped install a 150 on an 03 and the stock suction lines were too small. It was causing the pump to make weird sounds, so pumps that large may need larger than stock suction.

I've also installed a sump with a draw straw on an 05 and it has zero issues

On 11/13/2015, 10:19:45, Mopar1973Man said:

The only issue with smaller pumps like 95 GPH and 100 GPH you typically see a wider range of pressure change 3-7 PSI. Now a larger pump say 150 GPH which is very stable 1-2 PSI change from idle to WOT. Volume rate of the pump equates to pressure stability.

 

Those times with the smaller pressure fluctuation are when you could be out-flowing the filters. I would rather take a small pressure change and have fully filtered fuel at WOT (highest pressure on any pump) than full pressure and possibly some contamination. 

Like my set up I try to keep my pressures down. I don't like the 20 PSI and above crowd (personally). Like idling I'm 17 PSI and WOT its 15 PSI. Cruising it dances around the 16 PSI mark. But I'm running the AirDog filter (Donaldson) and stock filter (Fleetguard). So I really doubt I'm outside the rating of the filters since stock normal pressure was 12-14 PSI and I'm at 15-16 PSI under load.

While the flow should be similar at similar pressure it doesn't follow if any other modifications were made such as big line kits, injectors, fueling boxes, etc. Pressure is an indicator of resistance and not flow. My boost is a great example as I run 3-5 psi less than my stock cam/turbo with 100 more rwhp and lower EGTs. Flow is up and pressure is down.

The first filter on the pump also gets full flow all the time and last I checked they are not rated for anywhere near 150 GPH. 

The only thing I want to note here is pressure stability is the difference between demand volume and supply volume. So if you demand volume is lower than supply volume then pressure will be stable. Now if you demand volume is higher than supply volume then pressure will fall accordingly.

Quote

Pressure is an indicator of resistance and not flow.

Which is correct. So pressure falling out during WOT is a sign your demand volume is exceeding the supply volume.

This is basic pump class knowledge from Fire Fighting College Course. Same principals apply.

Edited November 17, 20159 yr by Mopar1973Man

34 minutes ago, Mopar1973Man said:

The only thing I want to note here is pressure stability is the difference between demand volume and supply volume. So if you demand volume is lower than supply volume then pressure will be stable. Now if you demand volume is higher than supply volume then pressure will fall accordingly.

 

Yes, mostly. The AD pumps are not of variable output and this is why they have their own dedicated return. The pump are always operating at a fixed rpm (which varies based on pump flow specs). The internal pressure regulator only pushes enough fuel thru the 2nd filter an out to the motor as needed to maintain the set pressure. If the change in flow is small enough the drop in pressure at the VP/CP3/psi gauge may not be noticed at the AD due to restrictions in the line in the form of fittings/additional filters/etc. Now if we get into a situation where the AD senses the output pressure drop and increases flow to the output (decreasing return flow) then yes a pressure drop means supply cannon meet demand, but only at that pressure. The demand is met with a lower pressure which is how the AD/FASS pumps work with a constant rpm pump.

So if your pressure drops and you had more than a small increase in demand it is safe to say the flow required to maintain 16psi worth of resistance isn't available but the volume of fuel is being met just at a lower resistance. The bottom line is filter are rated in flow not in pressure and flow is what we need to worry about when talking filtration efficiency.

It's been a while since I saw an AD or FASS flow vs pressure chart but one of those could better indicate how much one might be outflowing both of their filters by. As I mentioned the 1st filter is being out flowed on most, if not all, AD 150+ out there. The highest rated f/w sep filter I am aware of that fits the AD150 is only rated at 120 GPH.

With variable demand and flow (output, not input) it's hard to quantify a flow change with a pressure change. As the demand for flow increases the resistance changes and we see a pressure drop, but flow may be increasing due to the variable output from the AD even with a pressure drop. A 10% increase in demand from the injection pump may drop the resistance enough to require a 20% increase in lift pump flow for the same pressure.

34 minutes ago, Mopar1973Man said:

So pressure falling out during WOT is a sign your demand volume is exceeding the supply volume.

This is true if pressure is your #1 concern, but it's not with a filter. 100 GPH at 10 psi is the same volume of fuel as 100 GPH at 4 psi. Since I am talking filtration efficiency it doesn't matter if you are at 4, 10, 16, or 20 psi if you are flowing 100 GPH on a 60 GPH filter you are outflowing what the filter was designed for. There are filters listed for the AD150 that are only rated at 20GPH...