2.2 Tdci Puma (in-tank) Fuel lift pump specs

[Toxic_Avenger]

Just hoping to get a gauge on the specs of the 2.2 Tdci Puma (in-tank) Fuel lift pump.
For those unaware, the 2.2 tdci in the 2012+ pumas have a fuel sender / lift pump (low pressure) unit in the diesel fuel tank, whereas the 2.4's have the lift pump as part of the HP fuel pump on the engine.

For the purposes of installing a second diesel fuel filter, any idea what pressure / flow one might expect from the in-tank lift pump? Fuel filters tend to be rated by the Litres per minute (or gallons per hour) flow rate, and pressure that is expected to be seen in the system (I presume this is to prevent the filter medium collapsing).

Also hoping to get the general consensus of whether running a secondary fuel filter puts additional strain on the lift pump, and whether this is a potential issue long term.

[Toxic_Avenger]

More digging... more googling...

For the 2.4 (VIN 7A000001 > BA999999)
LR part number WQB100430 for the 90" in tank Fuel sender unit
WQB100440 for the 110" and 130" in tank Fuel sender unit

For the 2.2 (VIN CA000001 On )
It appears that the sender and the fuel pump are separate parts
Sender 90" LR030037
Sender 110" or 130" LR030038
The fuel pump is LR030039 (no differentiation between wheelbase).

This would make sense as the fuel tank is different sizes between the variants (needing different float heights for the sender etc), however the same pump assy is used (production efficiency, less stock on hand and all that jazz).

I believe these might be a VDO siemens unit.
The VDO website does not list a OE part for the defender that I can find, but it's a nightmare to navigate.

Microcat images for the 2.2 are below for those playing along at home


Still no info on flow rates though.

[alien]

Watching to see what you dig up with this one


I can't link the VDO pdf I found.
Page 179 lists Defender but no help for fuel pumps.

[Toxic_Avenger]

From what I understand, the lift pump would be tuned for flow over pressure... however pressure would be needed in the system to ensure that the HP pump can be 'force fed' enough diesel under high loads / fuel requirements to fill the pump chambers / pump elements.

The conundrum I have is twofold:
1) Adding a secondary fuel filter for the purposes of fuel system longevity (reduce risk of engine damage due to water and 'dirty diesel'). Marketing has us believe this is the goal.
2) secondary fuel filter with a smaller micron filter will create a flow restriction (AKA reduced pressure available at the HP pump) exascerbated when the filter becomes clogged with use. This can cause cavitation at the HP pump.

Some reading I've done suggests that in diesel systems, pressure is just as important as flow. Pressure is needed for charging the HP pump, and flow is used to allow additional cooling of the injectors and HP pump via the bleed off circuit and return to the tank via the fuel cooler. The fuel temp as it is pressurised to the 1600 BAR (ie stupid high pressures) would be rather significant, and the fuel cooler comes into play to share this thermal load with the engine coolant system.

Where potential issues arise is that a secondary fuel filter will add a flow restriction, and cause a pressure drop at the HP pump.
This pressure drop, at high loads could potentially lead to the HP pump pulling a vacuum on the supply side of the fuel system, leading to cavitation, and potential damage as a result.
The question then becomes... did LR (with all the resources available to them) have this same conundrum? Did they need to trade off fuel flow and pressure with the risk of cavitation, and if so, did they meet the right equilibrium?

All tough questions... well above my knowledge level. There's probably even a number of holes in my understangin in the wall of text above.. so chime in if I've got it wrong.

[roverrescue]

Mitch,
I see what you are trying to achieve. Wonder if the following helps at all.

I found these jiggers this week
https://www.dieselfiltersonline.com/...ries_rfcm.html

My current plan is to run one of these between a 70L under tray sub-tank and the main tank. Im thinking along the lines of running the 2 micron elements. I can then essentially scrub or polish fuel from the sub tank to the main tank. So always fill the sub tank, transferring across to the main filters it before it even gets to the LR filter. Also if I plumb it wisely - in a situation where I need to prime my 2.4tdci I can link the Parker unit to the existing LR filter and it will prime the system, then return plumbing to original layout. I will ensure that all fuel fittings enable this function.

I wonder though if you installed a similar unit between the tank and the existing LR fuel filter, it would as an extra pump at the very least overcome the added resistance of the extra filter? Thus pressure effects could be largely ignored, just ensuring that 40GPM or 50GPH is enough flow... assuming you are burning at worst 15L/100 then even the 40GPH is still flowing ten times what you are burning... I cant imagine the HP pump runs a 10:1 ratio cooling to burn?

I assume you were perhaps intending to remove the factory pump and run a higher rated pump with two inline filters...

How about go Marine Diesel crazy and run the above mentioned parker setup but run it as a fuel polisher - pump always running just cycling through the tank? Pickup near the bottom flow out near the top. at 40GPH on a full tank of fuel it cycles through the entire fuel load in half and hour? Never heard of it on a 4by but common to run fuel polishers on boats - albeit they are much more fancy and expensive than what I just suggested


Anyways an idea...

Steve