Replacing OEM Fuel Filters with CAV System

Couldn't agree more.

Everyone knows that Nissan has been annointed by the 'god of perfection' and can't be improved on.

Thats why I can't understand how 70% of posts on every page of this forum are from Nissan owners, screaming, bitching and kicking about their 'imaginary 4WD truck' problems.

I am guessing that Nissan in their infinite wisdom have engineered their machinery to such fine tolerances, that one poofteenth over OEM specs and the whole she-bang implodes.

So! Nissan owners heed the mans advice and don't take the chance.

Lucy,
I would be interested to know what effects at 3000 revs pump cavitation causes? Indeed, what is it? Does it by any chance cause a hesitation in engine acceleration similar to the feeling of fuel starvation?
Thanks for the help.

Good afternoon Michael.

Mate! go to the head of the class, you have hit it in one.

I don't mean to tell you or anybody else how to suck eggs here, so I'll do my best to explain it understandable plain english.

In essence all any type of pump does is create high presure on the outlet side and low presure on the inlet side to it, with the low pressure part variously described as the suction/lift/drag/pull etc capacity/capabilty.

This in turn creates a vacuum(low presure) on the inlet side causing the fuel to flow (be sucked/dragged) to the pump, with the pump then pushing it on to where it has to go at whatever presure the pump is designed to operate at.

Very basicaly (no physics engineering debate here) cavitation occurs when the flow to the pump is insufficient - for WHATEVER reason - for the pumps output pressure requirement.

In the case you and I are talking about i.e. Diesel engines in vehicles with constantly changing RPM's the usual effect of cavitation is that when the engine hits the critical RPM (what ever it may be) there is insufficient fuel to keep the RPM'S increasing without being impeded.

YES! the effect can be adequately descibed as:

' Does it by any chance cause a hesitation in engine acceleration similar to the feeling of fuel starvation?'

1HZ motors use this type of fuel flow system. Obviously the OEM engineers forsaw no reason to use inline booster pumps prior to the filters.

It just so happed that the critical RPM level on my 1HZ Troopy was 3000 RPM.

In my case the case the fuel flow was being impeded by the 'drag effect' through the filters. In essence, filters are just a blockage (but a necessary one)in the fuel line before the pump.

It made not one iota of difference that I changed the two filters every 5000Km and watched the fuel quality like a hawk.

There are a number of ways of eliminating this problem.

I personally took the option of changing the OEM filtering system to the CAV sytem for a number of reasons that all suited myself and how I operate.

This is not to say that what I do is good for everybody else ( this line is just for those who forgot to take their pills today).

I did play around with the idea of in line pre-aux fuel pumps, however in the end its just more mechanical trhings to go wrong. What convinced me on this was the NISSAN problem that occurs ' too intermittently' when pumping between fuel tanks.

Hope this sheds a bit a light on it for you.

Ken Robinson

Thanks Ken' Very interesting as I do get the effect at times and put it down to a dirty filter. Maybe not.

Excuse me! How can Landrover have the Perfection Title when Nissan beat you to it.

Ok! Mr smarty pants you have obviously been listening to the Verbal Diarrhoea exposed by the honorable member for Terang.

(1) It wasn't a tree, it was hedge that I attacked at dusk after deciding on the spur of the moment to give it a haircut under lights.

Up on the alinium plank on aliminum ladders with the electric 'swordfish bill' trimmer and away I go.

First swipe and the 'mother' stops. Hmmm! quick peek shows the power cord hanging by a wisp of plastic insulation.

B u g g e r! - blew the safety switch which I use religiously these days
after my good old dad was terminated with a power tool, and the circuit breaker after that. Must have been a good whack.

(2) This x-mas tree thing has me beat because your informant/lagger did not get to witness the alleged incident. Not for the want of trying mind you. He just had to rely on my blabbermouth SWMBO's (Ooops meant navigator) account of it all.

It just so happened that after submarine-ing through mountain rivers, water ingressed a multi plug somewhere that caused every b a s t a r d light on/in the dash to illuminate including the t-belt light.

Other than that everything was running as per normal. (Thats a Toyota for you - indestructible)

First thought was 'holy CHIT batman' whats next.

Well whats next turned out to be - leave it running and all returned to normal within a minute whilst running interference on your lagging informer to stop him seeing it.

And a good time was had by all.

(ROFLMAO) The things that we do.

PS

For the electrically hysterical - I had my mega thick soled Blunstones on when cable chopping incident took place.

hahahah My work is done hahahahaha

Yes I do!

Whats more I get a 10 pack under $40.

Also removing the Toyota pre filter, I have totally eliminated pump cavitation at 3000rpm which for those that know what that is, will immediately understand the benefit of same.

For a quick inspection I can take a peek down the side and check the 'seperator' and 'filter unit' for water and chit'

To service, its the removal of 2 12mm bolts (under a minute), lift the whole unit up and out of the engine bay - still attached to the inlet/outlet fuel hoses.

The position you see it in in the pic doesn't show how far it can be lifted up and out (only had one pair of hands when taking the pic)

SERVICING:

Both units have drain taps/cocks

I use DELPHI filters which I have been told and verily believe( nice legal term that which means I can't be held accountable for it) that the DELPHI filters are in the finest micron levels for these type of filters.

Whatever if there is: - no water, dirt etc on inspection and the fuel flow is OK, then it stays put.

I always carry two spare filter packs which a compact enough to squeeze in somewhere.

Just as an aside:

When serviced by the 'shops' they always changed the final fuel filter which was about the $45 mark and never ever looked at or changed the pre filter which is about $12.

When queried about this they told me - ah! mate you very rarely have to change that one and it has the electronic sensor in it to tell you if there is water in the system anyway.

It took me a while to wake up to that one.

Anyway now that it is clear of the leasing contract - do it all myself and know it is done.

Willem, you are preaching to the converted here.

I am definitely going to be a NIssan man in my next life on earth.

However, until that happens I have made a concious decision to suffer the imperfections of Toyotas as an atonement for all my sins.

I find it a much more carthartic experience than going to church to pay them off. (LOL)

Glenno,

(1) The one on the left without a filter is called an 'agglomerator' (think thats how you spell it).

Its purpose is to 'agglomerate water and other heavy chit in the fuel by droping the fuel on entry (Top centre) onto a fine veined cone which causes the fuel to flow downwards in a 360deg fine film into the retaining glass bowl on the bottom.

In theory the water and heavy particles seperate from the fuel, drop to the bottom of the bowl and agglomerate where you can see it.

The fuel then passes into the filter unit.

(2) The fuel Filter Head that I have used is the CAV one with the hand priming pump in it. You can use the swivel plate one attached to the OEM head by all means.

To each his own.

(3) Therefore if you wish, you can retain your OEM pre Filter and secondary filter head. Attach a CAV adaptor plate and use the CAV final filter system.

(4) I have no knowledge at all about how many filters of what ype you can run in line.

However I do know that when I had the Aux Belly tank fitted, they fitted an extra multipurpose type in line filter (Ryco straight through plastic petrol jobbie) which catches/picks up sticks and all sorts of junk.

This one gets replaced every 5000kms.

NOTE: I have used Banjo bolt fuel line fittings to facilitate the position in which I have mounted the unit.

You can specify straight in type fittings when purchasing if it suits your needs.

Evening Wayne.

All this stuff is personal preference and delphi filters have their limitations as well as all the others.

The post was not as to what is better or worse but one way of fitting CAV filter units into a vehicle.

Personally I change at 10,000kms, regardless. Never had reason to change under that.

Also that ryco in line filter that BrownDavis included when installing the belly tank gets changed every 5,000kms because it seems to collect a majority of the visible CHIT.

The $4.00 price is for a bulk buy and I am will bet that you or anybody else on the forum can't get within cooee of that price. But thats secret LUCY business.

Days Anecdote:

Guy where I work lives alongside a NISSAN service manager.

One particular day a customer comes in to collect his fabulous mega dollar Nissan ( urban sedan) after one of the warranty mandatory services and was given the bill.

$96.00

Threw an absolute wobbler because the price was so low that 'they couldn't have done anything' and demanded that they do what they hadn't done.

Service manger: one minute sir, let me check that account again for you.

Goes out of sight, generates another account for the subject vehicle with all sorts of fictitious service items on it and returns to the customer.

Serv manger: terribly sorry sir, another vehicles service details was inadvertently placed on your account. Here is your correct account , its $556.00

Customer : thats better, I new it was too cheap.

Moral of the story - another satisfied NISSAN driver.

Axle

Couldn't agree more and when I was a kid in the bush in W.A. all the farm diesel machinery and trucks in that era (1950-60s) all had those glass bowl sediment traps near the fuel source.

Matter of fact, one of the things done each morning was drain a bit out of the tractor ones which were left out in the paddocks at the mercy of the elements.

Just wish Toyota design engineering would take a hint or two from history re fuel systems. (I might send them an email suggesting they have a chat Landrover engineering-LOL).

Regards

Ken Robinson

PS

I am not adverse at all about pinching a good idea from others. Its just that 4WD OEM's other than Toyota don't have very many - good ideas that is. (ROFLMAO - better stop before I go too far - Oops! still ROFLMAO)