Hi All

I'm running a 2002 Hilux 4x2 3L EFI diesel. I'm wanting to fit an extra inline glass case fuel filter just before the main fuel filter. I've got a new filter here but the packaging has a sticker that says " Not suitable for fuel injection". I've read in a few places that an extra filter may be advantageous but I'm not sure if my fuel system will be happy with it in place.

Does anybody out there run an EFI engine with an additional fuel filter with no problems? Any other suggestions or insights?

Many thanks in advance.

This would be my guess as to why the filters may be marked as not suitable for injection....

I have had to change the fuel Pumps and filters on a few different Petrol engined cars with injection. The modern approach ( read lousy idea but you save 5C on every car you make) is to have the high pressure fuel pump in the tank before the fuel filter pushing the pressurised fuel through the rest of the system including the filter which is on the high side of the pump.

The cars I have worked on like this all have quite substantial metal filters which I suspect are designed to handle the 40-80 PSI fuel pressue I am told some sytems develop. Perhaps the filter you have is designed to be used on the lift side of a pump or on a low pressure system like on a carburettored car which probably has a max pressure of 8 psi if that.

Conventional type diesels may only have a low pressure feed pump which usually draws through the filter to ensure no rubbish is injested by the pumps. This is the way it should always be done but it seems if manufacturers can save anything at all by cutting corners on bad engineering practice, they will.

I believe some of the more modern diesels run fairly high pressure lift pumps that feed the injector pump and but if your setup is the more conventional kind that the pump draws through rather than pushes through, you shouldn't have any problems.

Maybe to this end the filter you have is designed to resist collapseing under vacum by having fuel drawn through it rather than being built not to explode by having high pressure fuel pushed through.

RossH
I don't have an EFI engine but I would be looking into this quite a bit more before I put an extra filter inline (extra resistance).
You main pump draws it's fuel from the tank and unless you have an electric pusher pump putting an extra filter inline could be an issue.

Your have to remember that the main fuel pump is the heart of your engine and it has been calibrated exactly to make your engine run at it's very best and increasing resistance will upset that calibration.
I have and a couple of others on this list have installed Walbro (pusher pumps) or other electric fuel pumps to our fuel systems and they can and have made huge improvements in how the engine runs. We are decreasing resistance to get these improvements and you are going the other way...Can't be good.
I also replaced my factory Fuel filter with a CAV adaptor and filters are only $6 instead of the Toyota $50 jobs.
http://www.biofuelsforum.com/using_b...y_on_bd-2.html

BTW why do you want to do this anyway? Cost of factory filters? better filtration?

__________________
HDJ80 (aka Kiwipete)
Canberra

Hi HDJ80

I'm going to need a little educating I'm afraid.

My understanding is that on my EFI system there is an electric fuel pump in the fuel tank which pushes fuel up to the factory fuel filter and in that, the system is pressurised. Would adding a pusher pump, perhaps up near the factory filter, aid in this fuel flow setup? In what way?

The reason I wouldn't mind putting in an inspection filter is so I can see any gathering of nasties and perhaps preempt a major filter blockage.

What I would have to say, and it concerns me greatly, is the rate at which the engine churns through BD. I haven't done an exact calculation yet but I assure you, the fuel gauge goes down quicker than a $30 hooker. I fully intend on quantifying this but regardless of the actual figure, the point will still remain that consumption has seriously increased.

Could this have something to do with this pressurised system and the viscosity of BD? Any other suggestions? I'd really like to ponder this one. When I say, consumption is up, I really mean it. Just through the roof.

Many thanks in advance.

I've got 3 pumps in my LR, a primary tank in the pump, which primes the secondary (lifter) pump in the engine bay. From there, the fuel goes through a fuel filter before it hits the chain driven high pressure injector pump that supplies fuel to the common rail.
I decided to fit a CAV filter before the secondary pump, as I did not like the idea of the secondary pump being killed by crap in the fuel. Also, this was handy for biodiesel if ever I would have to change filters while bio cleaned out my system.
I think the CAV filter is large enough to not offer significant resistance to the other pumps, whereas a single in-line filter may well drop the pressure a little.
I've not tested this scientifically, but it is just my gut feeling that a CAV filter would have a much better flow than a cheaper in line jobbie. So far I'm happy.

__________________
Robert.
Site Admin.

Hi RossH,

I have been using BD pretty consistently now since Oct last year - only one complete fill of dino since then plus a couple of "top ups." This is in a 3.2 DiD pajero. Mostly B100, plus a drum of B50, and the last couple of fills via VP's unknown (B80??) blend.

Generally I have seen a slight increase in consumption, although I have not been able to do accurate consumtion figures, given alot of my fills have been from a drum and pretty rough guesstimates of litres only.

But I was surprised to read your post which indicates dramatic increase in consumption. There are a few engineers out there who may wish to comment, but a dramatic change in consumption would not seem to be directly related to BD. I've read of others who have noted slight increases, even someone claiming better consumption from BD, but never dramatic changes.

Might need further investigation.

cheers,

Geoff.

Think about putting an inline plastic Ryco filter before your main filter ,it is cheap $4-6, no need for fuel line changes and is see through plastic so that you can see when it has a lot of rubbish in it. I have put one in each car and they work great. Once the tank is cleaned with the Bio,usually about 1000 klms filters last a long time. I do admit I filter the Bio as I pump it into the tank.
I was going to put a glass filter in line but was advised by my mechanic it would put more load on the fuel pump and his question was Why!!!!That is how I came to the small plastic ones.
Cheers Oily

The reason that the filter is not reconmmended for EFI systems is that in petrol cars ,the EFI used pump pressures in excess of 70 psi.

What you need to determine, is the pressure your fuel pump delivers. If the pressure is less than 20 psi, most fuel filters should be able to handle the pressure. Does you vehicle have a filter in the fuel delivery line after the fuel pump?
Can your fuel pump be removed from the tank easily? It will have a strainer on its suction line that you may need to clean during the first few tanksfull.

Tony

Hi Tony

I've just crawled up under the car and the fuel pump looks to be mounted on top of the fuel tank ie. not easy to get out without the car on a hoist, draining the tank then dropping out the fuel tank.

I'm thinking skip the inspection fuel filter. I do filter the BD extensively on the way into storage from the mixing drum and again when pumping it into the car from storage. The extra filter could well be overkill.

While discussing filtering fuel, it's worth mentioning the state of my blocked fuel filter that is used in a transfer/filtration system I have set up. My initial guide to making BD was a book called "Simply Biodiesel". The author briefly discusses washing your fuel but treats it really as an optional extra. So that's how I made my first batch. Got the reaction, tapped off the glycerin, let's go! Hmmmmm...
This unwashed fuel is the only fuel that this filter has cleaned and it is now useless. After taking it apart, I found large deposits of white gel clogging the filter material, I assume it is soap and glycerin. Further more, the paint coating on the bottom of the filter is peeling off, indicating to me the presence of probably methanol.

After discovering the bubblewashing technique and having seen the amount of soap and other gunk it clears out, I can't imagine not washing the fuel now.

Anyway, I did change the main fuel filter on the car after the first tank of BD though it was running fine when I did it. I've got to say, the learning curve with this BD is a little steep at times.

Ross,
The white stuff in the filter you opened is more likely to be high melting point biodiesel than soaps and glycerol. If you still have it, take a sample and heat it above 50°C. If it melts then it will be high MP biodiesel. If not, get some water and see if it soaps up, if so it is soap or glycerol.

If you can find a place where you can mount a pre-filter, put one in and try it out. The worst case siuation is that the filter splits and you lose some fuel. Do this in a non sensitive area - the front lawn is not suitable
If the cheap $2.00 filter works, use them, otherwise use a metal cased filter. They will still be cheaper than replacing the stock T0yota filter on your Hilux.
Tony