Lift Pump Question

[Marcus2000monster]

If I'm Lucky enough to get a refund from taxes this year I would like to purchase either a DTT Assasin or A FASS Titanium 95 or 150.

My question is must I modify the stock fuel lines or put in a sump if I go the Fass route or can I reroute the stock lines to the pump? 

[dripley]

You don't have to but you will want to. Without the bigger lines you will see alot of pressure drop due to the stock lines being so small. No sump is needed, you can pull right from the fuel basket with some modifications. Kits are readily available for that purpose.

[Marcus2000monster]

17 minutes ago, dripley said:

You don't have to but you will want to. Without the bigger lines you will see alot of pressure drop due to the stock lines being so small. No sump is needed, you can pull right from the fuel basket with some modifications. Kits are readily available for that purpose.

Basically I will need to run new lines from the top of the pick up basket on the fuel tank? 

[Mopar1973Man]

Do not use any of the stock lines not worth it. I would replace everything and put 1/2" lines from the tank to the VP44. I would keep the stock filter basket and fuel heater. I was sure happy to have that fuel heater yesterday at 2*F above kept the fuel at about 52*F rolling along at 55 MPH. The other thing makes sure to get the fuel lines out of the blowing wind I know that tough with an Assasin pump on the front. Then you're going to need to add a priming pump and check valves so if the system ever goes dry you can get the truck started again. Or pack around a fully charged drill so you can spin the pump. 

 

This is a few reason why I never went to the mechanical pumps. When my AirDog dies I'll go back to AirDog again risky? Maybe...

[dripley]

In a since yes but basket has to be modified for the pick up and the extra return line. Could be a little different for the FASS vs the AD that I used.

[Mopar1973Man]

If you didn't know a majority of my fuel line is INSIDE the frame. Nice access hole near the AirDog and comes out right about the bell housing and to the stock filter basket. 

[dripley]

1 minute ago, Mopar1973Man said:

If you didn't know a majority of my fuel line is INSIDE the frame. Nice access hole near the AirDog and comes out right about the bell housing and to the stock filter basket. 

Mine too. Easy to get it in there.

[Marcus2000monster]

35 minutes ago, Mopar1973Man said:

If you didn't know a majority of my fuel line is INSIDE the frame. Nice access hole near the AirDog and comes out right about the bell housing and to the stock filter basket. 

That’s what I’m going to do!

[Brignac]

If you go the mechanical route i recommend GDP's (Glacier Diesel Power) Fuel boss. Ive had it on my 01 for almost 4 years now and have never had any issues. I also still have the carter pump that is connected through the hobbs switch for priming purposes. If the fuel boss ever fails the carter should keep me from being stuck. But the only thing I feel that could potentially happen to the fuel boss is the belt break but I spent the $7 to keep an extra one under the back seat just incase it ever did decide to come off. To top it off Richard with GDP is an awesome person to deal with, and great customer service. I will be ordering the GDP mk7 fuel filter set up before to much longer as well and a Beans Diesel sump. 

[Marcus2000monster]

5 minutes ago, Brignac said:

If you go the mechanical route i recommend GDP's (Glacier Diesel Power) Fuel boss. Ive had it on my 01 for almost 4 years now and have never had any issues. I also still have the carter pump that is connected through the hobbs switch for priming purposes. If the fuel boss ever fails the carter should keep me from being stuck. But the only thing I feel that could potentially happen to the fuel boss is the belt break but I spent the $7 to keep an extra one under the back seat just incase it ever did decide to come off. To top it off Richard with GDP is an awesome person to deal with, and great customer service. I will be ordering the GDP mk7 fuel filter set up before to much longer as well and a Beans Diesel sump. 

IS there any reason why you would do the gdp over the Assasin? Iv heard very good things bout both pumps. 

[Mopar1973Man]

39 minutes ago, Brignac said:

and a Beans Diesel sump.

 

Don't do the sump if you smart. When you end up with a leaking fuel tank and you end up hunting wrecking yards looking for a fuel tank its not fun. I've already heard from 2 members that ended up replacing their fuel tank because of unfixable leaks.

[Brignac]

1 hour ago, Marcus2000monster said:

IS there any reason why you would do the gdp over the Assasin? Iv heard very good things bout both pumps. 

No as i have never used the DTT. Ive seen throughout forums people remove them because of 1 problem or another and have seen some used units come up for sale. Not saying the fuel boss doesnt, but i havent seen any. 

Here is 1 or probably 100 threads regarding, comparing, etc the 2 pumps from the cumminsforum. 

http://www.cumminsforum.com/forum/94-98-performance-parts-discussion/1506682-dtt-assassin-vs-gdp-fuel-boss.html

38 minutes ago, Mopar1973Man said:

 

Don't do the sump if you smart. When you end up with a leaking fuel tank and you end up hunting wrecking yards looking for a fuel tank its not fun. I've already heard from 2 members that ended up replacing their fuel tank because of unfixable leaks.

Well i also thought and considered just doing the drawstraw put didnt really want to drop the tank, yes lazy i know. And i've heard nothing but good things about the beans sump. I guess ill go back and reconsider just doing the straw. 

[Mopar1973Man]

The other problem with sumps is like another member is finding out is the gelling of fuel is more prone to happen being there is way more fuel exposed to blowing cold air in minus weather. Where a drawstraw all the lines are high against the bottom of the cab where there is way less air movement.

 

Like my last down to Onrtario, OR was 2*F above. Fuel pressure was down nearly 4 PSI from typically. Quadzilla reported fuel temp in the VP44 at 52*F that's with all the things I've done. AirDog behind the transfer case, fuel ines inside the frame, stock fuel filter housing being used and kept the fuel heater. Now imagine the fuel lines from the sump and running to a mechanical lift pump in the front engine and then to the VP44. I doubt it will fair as well as I've been doing. 

 

History to this day I've NEVER gelled up yet. I've never used any anti-gel or cetane booster product in the winter time. My coldest day yet was right at -35*F recorded in the truck and never had any issues. 

[Marcus2000monster]

1 minute ago, Mopar1973Man said:

The other problem with sumps is like another member is finding out is the gelling of fuel is more prone to happen being there is way more fuel exposed to blowing cold air in minus weather. Where a drawstraw all the lines are high against the bottom of the cab where there is way less air movement.

 

Like my last down to Onrtario, OR was 2*F above. Fuel pressure was down nearly 4 PSI from typically. Quadzilla reported fuel temp in the VP44 at 52*F that's with all the things I've done. AirDog behind the transfer case, fuel ines inside the frame, stock fuel filter housing being used and kept the fuel heater. Now imagine the fuel lines from the sump and running to a mechanical lift pump in the front engine and then to the VP44. I doubt it will fair as well as I've been doing. 

 

History to this day I've NEVER gelled up yet. I've never used any anti-gel or cetane booster product in the winter time. My coldest day yet was right at -35*F recorded in the truck and never had any issues. 

So your saying that for gelling sake you would not do  a mechanical cause its mounted on the front?

[Mopar1973Man]

The pump is in the blowing cold wind subzero. Way more length the pump is sucking fuel from the fuel tank. Sad to say no pump is designed to suck fuel. This why all manufacture started putting the fuel pump in the tank. Even with our truck we pull the pump off the block and moved them back towards the fuel tank and reduced the suction or lift the pump has to deal with. 

 

So I'll give you a milkshake and then give you a 20 foot long straw (1/2" diameter) and tell you to suck that milkshake while you sit in subzero weather. I bet you get rather frustrated. 

Edited February 15, 2018 by Mopar1973Man

[jlbayes]

I have had a sump for over 3 years with zero leaks. There is absolutely nothing wrong with using a sump. Pick the right one however. I.e. single mounting bolt retention.

[JAG1]

I like the idea of a sump because it's much simpler design. The drawback is potential clogging from everything collected at a single low point in the fuel system. Don't really know for sure.  I would like to try one but my reading has led me to believe they are illegal on a fuel system.

[jlbayes]

Legality of the sump is moot point with all the other crap I have on my personal truck. I doubt the 12v will ever get one just due to the fact it is of no benefit for the goals of the truck. The 24v on the other hand.....all the fuel flow I can get.

[Mopar1973Man]

@Marcus2000monster This is what I'm talking about as diesel fuel starts to gell become semi-solid its got to pull (suck) it longer distance. Pumps can push better for longer distance than they can suck or lift. Basically the parafin wax starts to clump together and thicken.

 

Edited February 15, 2018 by Mopar1973Man

[Brignac]

32 minutes ago, Mopar1973Man said:

The pump is in the blowing cold wind subzero. Way more length the pump is sucking fuel from the fuel tank. Sad to say no pump is designed to suck fuel. This why all manufacture started putting the fuel pump in the tank. Even with our truck we pull the pump off the block and moved them back towards the fuel tank and reduced the suction or lift the pump has to deal with. 

 

So I'll give you a milkshake and then give you a 20 foot long straw (1/2" diameter) and tell you to suck that milkshake while you sit in subzero weather. I bet you get rather frustrated. 

Idk my fuel pressure with the fuel boss idles at 17-18psi and when cruising sits at around 18-19 and wots between 20-22psi. So it seems the fuel boss is sucking pretty well through the factory straw. I dont think adding the straw or the sump would help increase that, which isnt needed, but I'm sure it would be less restrictive which is the point.