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Naf



Member Since: 07 Dec 2016
Location: Sandbox
Posts: 412

Kuwait 2000 Defender 130 Td5 HCPU Nato Green No Canopy
Td5 Fuel air separator
As i am pushin my TD5 past its comfortable limits, i find my fuel pressure at the head playin alot from 40psi up to 80psi.

My thought to solve this is to remove the fuel filter and replace with a lift pump. I will have the LP side go through a cooler, and the HP side feed the Lift pump. Set the lift pump to 65psi and let it run off a parallel relay for power.

This should steady my fuel pressure at speed and offer better fuel delivery as it is removing the air from the diesel.

Your thoughts?

Oh stock pump flows 47gph at 60ish psi. The low side flows 8gph at 0.75bar.

I want 70gph at 65psi Can't leave well enough alone
Post #846689 28th Jul 2020 4:03pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 7664

2011 Defender 110 Puma 2.4 USW Stornoway Grey
what sort of bhp are you pushing? we ran a highly tuned td5 that didnt have issues with stand alone aftermarket electric fuel pump to meet demand. Cheers

James
110 XS Utility
130 Puma Station wagon/camper (in the making)
90 Puma Hardtop
Post #846698 28th Jul 2020 4:22pm
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Naf



Member Since: 07 Dec 2016
Location: Sandbox
Posts: 412

Kuwait 2000 Defender 130 Td5 HCPU Nato Green No Canopy
I am somewhere in the clouds above 250 but below 300.

The bosche 044 pump flows more than the stock pump.

By removin the air i am also makin the mixture more predictable and with an extra fuel cooler, i should see better overall performance. Can't leave well enough alone
Post #846704 28th Jul 2020 4:27pm
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jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 7664

2011 Defender 110 Puma 2.4 USW Stornoway Grey
ours was a tad over 250, measured. I can't recall aftermarket pump. But had that and no i tank pump.

Be warned, engines don't last long. Cheers

James
110 XS Utility
130 Puma Station wagon/camper (in the making)
90 Puma Hardtop
Post #846768 28th Jul 2020 9:14pm
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bankz5152



Member Since: 02 Feb 2017
Location: South London/North Kent
Posts: 2049

2004 Defender 110 Td5 DCPU Epsom Green
Sure its not your tank? Getting fuel starvation? Instagram @defender_ventures
Empire Tuning - Agent
Post #846790 29th Jul 2020 6:41am
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Naf



Member Since: 07 Dec 2016
Location: Sandbox
Posts: 412

Kuwait 2000 Defender 130 Td5 HCPU Nato Green No Canopy
I like to keep the fuel levels above 1/2 a tank.

I also have a fuel pressure sensor on the line before the regulator on the head. So I have an accurate reading of what is there.

I played with the fuel regulator. I installed one with a pressure nipple and bumped up the pressure so it would hold more pressurized fuel, but it didn't help. It was just as erratic but at a higher pressure. Can't leave well enough alone
Post #846792 29th Jul 2020 6:51am
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Naf



Member Since: 07 Dec 2016
Location: Sandbox
Posts: 412

Kuwait 2000 Defender 130 Td5 HCPU Nato Green No Canopy
More frequent oil changes, better oil coolin, and lots of 2T oil. 3ml per ltr of fuel.

Keeps mine runnin fine. Can't leave well enough alone
Post #846891 29th Jul 2020 4:31pm
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mturri



Member Since: 13 Jul 2010
Location: Patagonia
Posts: 26

 2006 Defender 110 Td5 CSW Bonatti Grey
Re: Td5 Fuel air separator
A healthy stock fuel pump outputs 180 litres/hour (HP stage) which should be more than enough flow rate wise. High flow is primarily needed so that the regulator can choke it so as to create the necessary back pressure for efficient injector fuel fill. Note that the regulator is actually downstream of the fuel rail, though it's location and the fact that it acts both as a fuel entry & exit point makes things rather confusing. Td5 injectors have an ultimate injecting capability of 90 mg/stroke, with an operating maximum (Td5 EMS) of 50-55 mg/stroke as out of factory. At peak power theoretical fuel intake is about 280 grams/min so roughly 0.33 litre/min ~ 20 litre/hour (very debatable finger math based on achievable engine speed versus driver demand and ignoring all limiters so actual figure should be significantly less). That's roughly 10% of fuel pump delivery capacity and a full tank in a little over 3 hours... some serious fuel burning!

Have experimented with 5 and 6 bar FPR inserts and did not experience any measurable performance gains (EBP/EGT).

Fuel temperature helps optimise atomisation which in turn maximises thermal efficiency so unless suffering from specific fuel heating issues (e.g. climate derived) decreasing fuel temperature will not do much for performance, perhaps even the opposite. IQ is mass based and that is what the inlet fuel temperature sensor is for. If fuel too cold EMS derates IQ to keep emissions at bay. If fuel too hot IQ is capped accordingly.

If fuel pressure erratic would suggest to check fuel pump current draw waveform, potentially bad section on commutator or even armature shorting, not necessarily indicative of impeding pump failure but may explain pressure swings & performance issues. 24 yrs of Td5 ownership
D110 Td5 MY06 fully tuned up
ex-D2 Td5 MY04 Auto
ex-D110 Td5 MY00
ex-D2 Td5 MY00
ex-D2 Td5 MY99
ex-D1 300Tdi MY89
ex-D90 200Tdi MY87
Post #847929 4th Aug 2020 2:16am
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