Improved Sub Tank fuel recovery

[JoeG]

:thumbup:
I recently increased my Sub Tank recovery from 28l to 34l by modifying the sender float arm and the fuel pick up
I bent both (well straightened more like by around 40mm)
I removed the sender again today to see how much fuel left and found 15mm to 20mm fuel still left so straightened more and added a short length of 5/16 fuel hose to pick up
Hopefully this will almost MT the tank in future.
I also noted that I can always get the pump to restart transferring when going up hill due to fuel flowing to the sender
So will MT tank tomorrow then refill and see how much I can get in
I can safely MT the tank since I have fitted filter separators to the Sub tank and Main tank to catch any sludge, I have also reversed the flow direction of the filters so the fuel travels to the glass bowl first then gets filtered so I can see any debris before the filter blocks
Regards
Joe

[patch697]

I moved your post into the DIY section mate as this is a good DIY job for those who like to modify.

[JoeG]

Hi
I just came back from the servo
The Sub Tank now takes 36l, so a 28% increase in fuel recovery
which should mean around 60km more range
Since I have the chassis lengthened I may now look for a 2nd original Sub Tank to fit
(i have measured under and seems to be enough room to fit a 2nd Sub Tank under rear seat)
Regards
Joe

[scotty83]

nice jobs.. looks good

[davejones]

Hi,

Where did you source your filter system? I'm guessing one is on the main tank line & the other on the subtank line?? I wouldn't mind doing this to my wagon. Also, did you have to modify anything on them to run them in reverse?

Dave

[JoeG]

Hi,

Where did you source your filter system? I'm guessing one is on the main tank line & the other on the subtank line?? I wouldn't mind doing this to my wagon. Also, did you have to modify anything on them to run them in reverse?

Dave
Hi Dave yes one is for the Main Tank the other for the sub tank
I purchased from the local auto store, the reason for ignoring the flow arrows is to allow the fuel to fall to the bottom of the glass bowl to let the grit and sludge settle
I did the same to my Hilux 200,000km ago and still on the same filters since the change, clean the glass bowl every 5,000km and always get some grit and some times sludge as well.
Good luck with your set upo it will have to be under the bonnet as you have the station waggon.
You won't have to fit one to the Sub Tank I had the space and chose to but it is not required
Regards
Joe

[davejones]

Hi Joe

I did wonder about the need for a second. Given that all the fuel goes through the main one.

Thanks for the reply.

Dave

[Tweakedoffroad]

good job well done what made you think of this

[JoeG]

good job well done what made you think of this
Hi
The Sub Tank looked bigger than 28L so decided to remove the sender to detect how much fuel left in tank when sensor stops pump.
Whwn I found around 5L left in tank decided to modify Sender and then fit a filter seperator as well.
With the main tank I had a disaster with the Hilux many years ago when I was working at Mt Piper Power Station (near Lithgow NSW)
we had a dump of snow and I found my self crawling in 2nd gear with no power Filled up with Álpine Blend at local servo and problem went away.
Next time the tank got down to <25% the same thing hapend, and this was at home with a balmy 25C not snow.
So I removed the fuel tank and sender- found to my horror the tank had around a cup full of black muck around the fuel pick up- removed the pick up and fitted the filter/seperator.
That was 1996 and still running on the same filters, as the seperator gets all the crap before the filter.
I always find grit and a bit of black muck and some times a few drops of water in the bowl when I clean it every 5,000km
Regards
Joe

[davejones]

Pulled mine out during the week. Mine had a filter where your fueul hose extension is in your pic.

I pulled the float arm off the sender - it just unclips if you're careful - and I'm pretty sure it was 150mm in the vertical drop to the centre of the float. I tweaked it at the first bend off the sender to make that 170mm.

I was already picking up 32ltr from mine. Now I reckon I'm getting closer to 35. I'll know more in a couple of days when I can do a transfer and fill. The servo I used had me parked a bit nose up but I'll go elsewhere and get a better idea.

I wonder how far you can go before the tank transfer pump won't cut out - of you bottom the float on the tank bottom. Measuring I don't reckon I could go much further.

Dave

[Rip'n'Shred]

Great idea, providing the transfer pump cuts out before the tank is empty. I suppose that's why there is so much left in aux tank from factory, ensuring fuel remaining despite angles.

[JoeG]

Fuel tanks are designed to leave around 10% in thew bottom of the tank for Condensate (water) to accumulate and the sludge and grit to sit.
They also fit a fairly fine plastic strainer on to the fuel pick up to hopefully stop the grit and sludge (leave it in the tank), however I've had issues with the in tank strainer blocking and having major issues with lost power.
So I have removed the in tank strainer and fitted the hose extension in order to get all the fuel, I then fit a in line strainer and seperator in the fuel line before the OEM filter
I did this in 1996 to my 1992 Hilux and have not had to change the OEM filter since, (200,000 km+)
I have now done the same to my Tractor, Pajero and Patrol
I don't like fixing blocked in tank strainers on the run much easier to clean a External seperator and in spect the in line disposable strainer every 5,000km
Jeo



Great idea, providing the transfer pump cuts out before the tank is empty. I suppose that's why there is so much left in aux tank from factory, ensuring fuel remaining despite angles.

[JoeG]

I wait till the Main tank is <1/2 full, then start fuel transfer, when the maintank stops rising and Sub stops falling I then press the Sub button again and the pump stops.
The sub pump is a self priming diagragham pump and designed to run dry for short periods.
Joe

[BEP120]

Good job on getting more out of the sub tank. The extra filters are a good precaution.

[sooty_10]

Nice idea, will have a look this weekend at mine. Will defintitely be putting a filter sepeartor on when I get the car back running.

[JoeG]

Just filled up
ran sub out and main to warning light
then fueled up 120L, and 970km, so average 12.3 L/100
Happy with that
Regards
Joe