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Discussion Starter · #1 ·
Hi All, in an effort to make working on the CRD engine easier, (and for reliability on longer trips) I'm installing a Diesel pre-filter and lift-pump, my unit is a late model vehicle with the rear aircon, and ABS, so my mounting options are pretty limited.

Because of this, I've made the conscious decision to not run a second battery under the bonnet, and i'm looking at using that space to make my life easier. I've got a Carter 4600HP lift pump here to install, as well as the fuel manager diesel pre-filter. What i'm looking at doing is moving the CRD fuel filter across to the passenger side, and mount it and the pre-filter right next to each other. It would involve custom brackets and a heat shield, but would make my life infinitely easier to maintain the fuel filter(s). I'm also toying with the idea of re-locating the oil filter into this area as well.

While I'm not a massive fan of running 2 fuel lines across the engine bay, mainly because of heat soak and the increased potential for bad stuff to happen, I've got to do that anyway and the benefits to having an easier to access fuel filter is pretty big.

Am I crazy?
 

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'14 Y61 ZD30 CRD M/T ST
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Straight off the bat, I don't see any issues with your plan, apart from the massive amount of work involved, but you seem to be aware that it's not going to be a 5min job.

IMO you need to take two things into consideration.
1. Whatever you do must not cause a restriction or reduce the flow to the CRD pump. As long as you can guarantee fuel flow and pressure to the CRD pump, it should be fine, so beware of introducing additional restrictions through Tees and bends. But I assume the Carter will compensate for this.

2. The CRD pump (and the Di for that matter) uses diesel fuel for lubrication AND cooling. Just make sure that the fuel doesn't pick up additional heat between the relocated filters and the pump. So shield them, especially routing around the turbo area.
 

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Hey @J0SHMAN
I've thought a bit about this.
A couple of things to consider:

-Have you measured how much flow the crd pump already has? Ie making sure the Carter isn't going to slow this down

- have you considered installing a cooler? As Andrie said above the fuel is also used for cooling so having it run through a cooler (like an oil cooler or an auto trans cooler) should help.

I'll be watching this with interest. I have a second filter and an oil cooler in the shed just waiting to go on, just havent prioritised it😉
 
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Other ideas-

Do you have a front mount intercooler? Or plan to?

If so, and since you are already running the fuel hoses right past, you could mount a cooler in the place where the std intercooler sits. Given an oil cooler's thin profile, you could easily fit an awesome thermo under it to ensure it was always saturated in cool air?🙂
 

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One thing I would add as well...

Although it seems logical to make the engine bay space easier to work in, at some point you won't really be working in it constantly (Yes even with a ZD30!)

I had similar thoughts too, but once my repairs and engine mods were all done, I haven't had to go under there for much.

If your dual battery is going in the back (good idea, I wish I had done so), then you really won't be under the bonnet frequently. There are some kits out there I believe that mount the catch can and fuel filter in that battery spot with minimal mods required

So just a thought about diminishing returns there. May be better ways to spend your time/effort/money?
 

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I agree with Jack. The effort and expense of replumbing is going to oughtweigh the few minutes you'll save each time you change your filters. As for reliability, adding extra componants like a lift pump and more lines can only decrease reliability as there are more points of failure.
 

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There's a big discussion over here about fuel filters. I believe some users such as @skegbudley have gone as far as to remove the factory fuel filter and replace it with an aftermarket unit which filters better and gives dash alarms when water is detected.

I only skimmed that thread, but they might be using filters like the following

Drivers side, with alarm

Drivers side, without alarm

Passenger side
 

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Discussion Starter · #8 ·
Alrighty, Thank you very much for the input, and there is a lot of sensible ideas and suggestions being thrown at me. as much as I'd love to have an easier time changing the fuel filter out, I don't need to do it often enough for this to be a worthwhile solution (for now). The lift pump (with parallel check valve) will still be going in, as will the diesel pre-filter, but I think i'll try and find another place to mount it, so i don't have to run fuel line across the top of the engine. I'd like to incoorporate a fuel cooler somewhere into my works as well, possibly down near the Lift pump?
 

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@J0SHMAN

What does the drivers side firewall corner of your engine bay look like? I'm not sure, but I think some of those direction plus kits mount it where I've circled in red. It's certainly a good sized spot for a filter on my 2009.

The big question is, does a CRD require a lift pump when adding a pre-filter? I wouldn't have thought so. Perhaps with a 3 micron post-filter it would.
From what I understand, the CRD lift pump is different to the DI.

Obviously if you're planning other fuel system mods, bigger injectors etc then maybe that's a different story. Not something I know much about to be honest

528793
 

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X2

I havent seen anyone here say how much diesel flows back to the tank in standard form. If this was measured we'd have a base to work from to understand if any mods restrict the flow and if the std crd pump is up to the task
 

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Discussion Starter · #11 ·
@J0SHMAN

What does the drivers side firewall corner of your engine bay look like? I'm not sure, but I think some of those direction plus kits mount it where I've circled in red. It's certainly a good sized spot for a filter on my 2009.

The big question is, does a CRD require a lift pump when adding a pre-filter? I wouldn't have thought so. Perhaps with a 3 micron post-filter it would.
From what I understand, the CRD lift pump is different to the DI.

Obviously if you're planning other fuel system mods, bigger injectors etc then maybe that's a different story. Not something I know much about to be honest

View attachment 528793
I wish i had the big blank space, in the later models, they've run that (air-con?) line slightly differently. I don't see why they changed it, as the previous version was much much better for working in the engine bay.
IMG_20200529_170825.jpg


X2

I havent seen anyone here say how much diesel flows back to the tank in standard form. If this was measured we'd have a base to work from to understand if any mods restrict the flow and if the std crd pump is up to the task
I've done extensive reading of the various lift pump threads. I've noticed in my own vehicle (and it was identified in one of those other various threads), that when the fuel level gets below half a tank the car starts to get gutless. To my layman understanding this is due to the change in head pressure in the fuel line (or possibly the increased fuel temp?). While i understand that a lift pump will have a greater positive impact on a DI than on a CRD, it shouldn't hurt to provide a positive pressure to the back of the fuel pump. (plus I might be able to get rid of that stupid primer bulb).

My understanding is that the CRD circulates quite a lot of fuel back to the tank, which is why fuel temp becomes a problem at low fuel levels. Ideally I'm going to try and fit a fuel cooler onto the fuel system to try and combat this. Still not sure if it's better to cool the return fuel, or the lifted fuel. though i;m leaning towards the return fuel.

The Carter 4600HP or 4601HP are recommended for this task because they're good for 100 gallons/hour (300+ L/Hr) the 4600HP is an 8psi pressure cut off, while the 4601HP is 16(?) Psi cut-off.
 

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I wish i had the big blank space, in the later models, they've run that (air-con?) line slightly differently. I don't see why they changed it, as the previous version was much much better for working in the engine bay.

I see.
If this is any help, I saw this pic on the zd30 facebook group. I would hazard a guess that this is one of those direction plus kit's brackets. I don't understand why the fuel lines are going down toward the front though. I would have thought they'd tap straight into the fuel line next to the primer bulb? I have no idea how these things operate
528860



I can see how your aircon line gets in the way, but maybe a bracket could still be squeezed in behind in? Wouldn't be hard to fashion something up. I used a rivnut gun and stainless rivnuts on the other side for my dual battery tray (pics in my thread somewhere) which is strong and looks factory, or at least way better than tek screws.
Otherwise, I wonder if it might be easier to replace that aircon line with one like mine to make some space? I'm sure you could pick one up from a wrecker, or Garry at Nizzbits would have one pretty cheap. In fact an auto aircon guy could fab you up one in whatever configuration you want... Obviously factor in the cost of a re-gas if you do change that aircon stuff, but still probably easier than moving the whole fuel system.


Regarding the lift pump, I'm way out of my depth but very curious. I've been wanting a fuel filter/water trap a long time but the kits are all for a 30 micron pre-filter. It makes more sense to me to have a <5 micron post-filter if protecting the injectors (not the oem filter) is priority.

In fact, replacing the factory fuel filter completely and just running an ultra fine filter/water trap is becoming pretty appealing to me
 

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Discussion Starter · #13 ·
I finally had some time and good enough weather to have a good and proper look around the engine bay for mounting options today and i've come up with a few:
  • move the washer bottle to the passenger side and mount it behind the driver-side headlight
    • a bit of work in moving the washer bottle, but has the shortest and easiest fuel line run.
  • make a bracket to mount it below the driver-side headlight behind the front bar -
    • best option for accessibility
    • could need some extra protection
  • make a bracket and mount it forward of the Provent, in the spare battery spot on the passenger side.
    • run the lift and return fuel lines in metal pipe across the front, forward of the radiator - use this as a way to help cool the fuel?
    • easiest way to insert a fuel cooler into the system - between pre-filter and OEM filter.

I see.
If this is any help, I saw this pic on the zd30 facebook group. I would hazard a guess that this is one of those direction plus kit's brackets. I don't understand why the fuel lines are going down toward the front though. I would have thought they'd tap straight into the fuel line next to the primer bulb? I have no idea how these things operate
I'm not sure about those fuel lines either, that a very odd arrangement, I'd love to install the pre-filter in that location, but i double checked it again today and it's definitely a no-go, I'm not sure what's in your engine bay regarding the brake system or how its plumbed (if different to mine), but i've got some lines in the way. to get my filter low enough, it'd virtually be riding on these hard-lines.
Inkedenginebay_topDS_cropped_LI.jpg


I can see how your aircon line gets in the way, but maybe a bracket could still be squeezed in behind in? Wouldn't be hard to fashion something up. I used a rivnut gun and stainless rivnuts on the other side for my dual battery tray (pics in my thread somewhere) which is strong and looks factory, or at least way better than tek screws.
there will be NO tek screws in the patrol. :sneaky: my Ol' Navara was held together with tekkies, never again.

Otherwise, I wonder if it might be easier to replace that aircon line with one like mine to make some space? I'm sure you could pick one up from a wrecker, or Garry at Nizzbits would have one pretty cheap. In fact an auto aircon guy could fab you up one in whatever configuration you want... Obviously factor in the cost of a re-gas if you do change that aircon stuff, but still probably easier than moving the whole fuel system.
This is still an option, but without knowing how the previous models got away with mounting it there and not hitting the brake hard-lines...

Regarding the lift pump, I'm way out of my depth but very curious. I've been wanting a fuel filter/water trap a long time but the kits are all for a 30 micron pre-filter. It makes more sense to me to have a <5 micron post-filter if protecting the injectors (not the oem filter) is priority.

In fact, replacing the factory fuel filter completely and just running an ultra fine filter/water trap is becoming pretty appealing to me
I've got the 30 micron pre-filter. my figuring is that the OEM filter is good enough for the injectors, thats what Nissan use and recommend. they're also bloody expensive. The fuel manager 30-micron pre-filter elements are (relatively) cheap and ubiquitous enough that i can get them easily, and will help prolong the life of the OEM filter.

If I find down the track that i want a post filter, it shouldn't be much more trouble than swapping the filter and a few hoses around.
 

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I think you’re all over this. I’m watching with keen interest.

one thing I’ll add, be aware of mounting anything behind the front bar... you may well end up with a front mount intercooler one day!
 

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Discussion Starter · #15 ·
Thanks Jack, I spent a lot of time (and money!) working and reworking and re-reworking stuff on the Navara. while I learnt a heap, it was a lengthy and often ill-considered approach to building a tough tourer. Lets just say it was a great learning experience.

Now because the Patrol is new to me, and in pretty mint condition, plus i've matured (somewhat) I'm taking a bit more of a considered approach to my build and researching and taking the time to properly plan ahead and make sure that i'm building the proper thing. there's a few things that are no-brainers - anything to improve longevity and reliability (though i haven't done the EGR yet) while still keeping it very neat and legal are my biggest missions with the patrol.

I was doing some more reading around on the fuel system last night and came across the following thread:

and in particular this post
I suggest you have a read of the linked white-paper, it's not too technical, but clearly lays out some easily digestible filter combination results and the associated pump/injector wear. This brief summary of the white paper from a few posts past that one is pretty telling:

The filtration test results are quite interesting particularly the last few.
#3 showed the filter increasing in efficiency then dropping off efficiency and actually releasing particles again repeatedly over time. Not the filter you want.

#4 with series two of the same filters showed better results.
But they did not explain the drop in pressure or flow or other parameters associated with this.

#5 shows the results of a larger filter to reduce face velocity and that is conclusively the best filtration and I would also assume the lowest resistance to flow rate etc.

So what we need to know is how that relates to the size, flow rate and efficiency of the OEM filters fitted to our engines. Are they already perfectly adequate or would it be far better to just fit the next size larger filter if one were available and suitable.
The thread isn't a bad read, but ultimately this white paper with real world testing results, from a reputable filter company really seals the deal for me.
 

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The thread isn't a bad read, but ultimately this white paper with real world testing results, from a reputable filter company really seals the deal for me
I haven’t fully digested that paper (currently sitting in a classroom where I should be digesting equally heady material), but definitely good to see some reputable research. I also put a lot of stock in Geordie’s opinion on matters like this.

so the 30 micron pre-filter + OEM filter appears a good combo. That’s good. I don’t quite understand what the advantage of a lift pump is then? I think a lot of people are running that combo without a lift pump.

Like you, I’m also concerned about over spending time, money and complexity
 

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Discussion Starter · #17 ·
I haven’t fully digested that paper (currently sitting in a classroom where I should be digesting equally heady material), but definitely good to see some reputable research. I also put a lot of stock in Geordie’s opinion on matters like this.

so the 30 micron pre-filter + OEM filter appears a good combo. That’s good. I don’t quite understand what the advantage of a lift pump is then? I think a lot of people are running that combo without a lift pump.

Like you, I’m also concerned about over spending time, money and complexity
My understanding is that the low pressure (tank) side of the injection pump operates at a vacuum, as it has to suck the fuel from the tank. So, as the fuel tank level gets lower, the head pressure available to assist the injection pump gets less. (random though - might also add to the power loss going up hills?)

In the Di model this seems to have a noticeable impact on the injection timing, meaning less power and more stress on the components. My understanding is that by adding a lift pump, you're now providing positive fuel pressure to the back of the injection pump and it's able to deliver the requested timing and provide optimal power delivery. I know there was a lot of discussion around how much pressure can you put in the back end of the IP before you start doing damage and I believe the consensus based on the US diesels using the same IP is that the little carter 4600 and 4601 won't be any problem.

I'm still not completely across the CRD as my ol nav had a Di ZD30, but just by going by my bum-in-seat dyno, i notice a definite difference in power between a full tank and a half tank (or less). which in my short drives, I can really only put down to the fuel tank head pressure.

I've also had the thought to install my 30 micron pre-filter between the tank and lift pump. I'm still very much undecided, which way to go, but it will some mental lubrication and spending a bit of time under the vehicle with the parts and a tape measure.

My end goal is that by adding extra filtration and by assisting the IP to do its job, I should extend the life of the pump and the injectors. and by virtue, make the vehicle more robust for remote touring.
 

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I'm still not completely across the CRD as my ol nav had a Di ZD30, but just by going by my bum-in-seat dyno, i notice a definite difference in power between a full tank and a half tank (or less). which in my short drives, I can really only put down to the fuel tank head pressure.
I think you're barking up the wrong tree here...

The top of a full tank is still considerably lower than the OE filter and the CRD pump, so I highly doubt that little increase in head pressure is going to make much of a difference. If anything, I think fuel temperature has a bigger impact. The fuel in these pumps get hot, even more so in the CRD because of the higher pressures. And we all know average fuel temp increases markedly when the tank gets empty bcause you're returning hot fuel and there's less "cold" fuel to mix it with. I'm not sure if the ZD30CRD system uses fuel temperature compensation, but some of the VW diesels I've had in the past, did. I think you'll probably see the biggest gain by adding a decent fuel cooler.

I'd be hesitant to push fuel up the backside of the CRD pump. It's not exactly a cheap piece of equipment. Don't get me wrong, giving it a positive feed is probably a good thing as fuel starvation kills these pumps as well, but exactly how much positive feed is the question...
 

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Discussion Starter · #19 ·
I think you're barking up the wrong tree here...

A CRD Wagon is suppsed to have 95+30 = 125 litres of fuel capacity. At 0.85kg/l that's 106.25kg. I think your super sensitive calibrated bum-in-seat dyno is measuring the weight difference, not the fuel pressure difference. Also, the top of a full tank is still considerably lower than the OE filter and the CRD pump, so I highly doubt that little increase in head pressure is going to make much of a difference.
If it were weight difference that i am feeling, shouldn't that mean that i experience better performance at lower fuel levels? where as my finely tuned posterior says the opposite - better performance at higher fuel level. (yes, temp will be a big factor)
Speaking in general relatives (and through the lens of a layman) - half a tank of fuel will have half the head pressure as a full tank, which means the fuel pump is getting half the assistance to pull from the tank = working twice as hard as with a full tank. I'm not across it enough to calculate any siphon effect that might be assisting the IP. Admittedly, this ability is (obviously) well within its operating specifications, however, this effect only gets larger as the tank gets lower. Taking the suction factor out of the equation for the low pressure side of a fuel pump can only make its life easier, and increase its longevity.

If anything, I think fuel temperature has a bigger impact. The fuel in these pumps get hot, even more so in the CRD because of the higher pressures. And we all know average fuel temp increases markedly when the tank gets empty because you're returning hot fuel and there's less "cold" fuel to mix it with. I'm not sure if the ZD30CRD system uses fuel temperature compensation, but some of the VW diesels I've had in the past, did. I think you'll probably see the biggest gain by adding a decent fuel cooler.
Fuel temperature is definitely a bigger contributing factor here as well. However, I'm only a 5-10 minute drive from home-to-work in the morning, so my fuel starts cold, and I wouldn't think that it has much opportunity to circulate and warm the tank up to make any appreciable difference in performance. Though if i take it for a drive up the other end of town and back I can absolutely notice the impact that a low fuel level, and consequently the temp, has on performance, that is very noticeable. and a big reason why i'll be putting a fuel cooler into whatever solution i come up with.

I'd be hesitant to push fuel up the backside of the CRD pump. It's not exactly a cheap piece of equipment. Don't get me wrong, giving it a positive feed is probably a good thing as fuel starvation kills these pumps as well, but exactly how much positive feed is the question...
This has been done before; I'm simply building on others experience. I'm not really chasing anything performance-wise with a lift pump, just increased reliability with a second filter and fuel cooler, and hopefully more longevity to the critical system components.

For reference, this old thread, while now devoid of pictures, still has some good anecdotal evidence for a lift pump in a CRD. By all accounts, the Patrol CRD not having a lift pump makes it the odd one out in the CRD market.
 

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After a long time coming back to this forum, although I browse a lot time to time.

I fitted my 2micron pre-filter around 150k kms and my car has done 230k kms now and so far didn't notice any fuel restrictions (changed the filter a couple of times I think).


If it were weight difference that i am feeling, shouldn't that mean that i experience better performance at lower fuel levels? where as my finely tuned posterior says the opposite - better performance at higher fuel level. (yes, temp will be a big factor)
Speaking in general relatives (and through the lens of a layman) - half a tank of fuel will have half the head pressure as a full tank, which means the fuel pump is getting half the assistance to pull from the tank = working twice as hard as with a full tank. I'm not across it enough to calculate any siphon effect that might be assisting the IP. Admittedly, this ability is (obviously) well within its operating specifications, however, this effect only gets larger as the tank gets lower. Taking the suction factor out of the equation for the low pressure side of a fuel pump can only make its life easier, and increase its longevity.


Fuel temperature is definitely a bigger contributing factor here as well. However, I'm only a 5-10 minute drive from home-to-work in the morning, so my fuel starts cold, and I wouldn't think that it has much opportunity to circulate and warm the tank up to make any appreciable difference in performance. Though if i take it for a drive up the other end of town and back I can absolutely notice the impact that a low fuel level, and consequently the temp, has on performance, that is very noticeable. and a big reason why i'll be putting a fuel cooler into whatever solution i come up with.


This has been done before; I'm simply building on others experience. I'm not really chasing anything performance-wise with a lift pump, just increased reliability with a second filter and fuel cooler, and hopefully more longevity to the critical system components.

For reference, this old thread, while now devoid of pictures, still has some good anecdotal evidence for a lift pump in a CRD. By all accounts, the Patrol CRD not having a lift pump makes it the odd one out in the CRD market.
 
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