Waynepd (NSW) replied:

I know there is an alternative setup that was spoken of in the Yahoo Patrol list, years ago. You can get a different set of manifolding ports that allow you to use the tanks in the way you describe for your cruiser....I just can't remember where you get them, sorry but at least they exist its a start.....
will investigate if no-one else comes up with the right answer....

howie replied:

i have been wrong before, but i was of the opinion that the the gu always runs off the main tank and when the 'sub tank' switch is pushed, it merely empties into the main.
there is a reason for the 5 second pump on start up, something to do with condensation and/or ensuring the pump is used.
when i'm in town and stopping/starting a lot i do notice the sub tank go down.
but it has not bothered me out in the bush.
my main tank also indicates about 3/4 full on a full tank, is there an easy cure for this anyone?

Member - andrew B (Kununurra) replied:

Gday Bilbo

I actually like the setup on the GU (everyone has their own opinion of course). For myself I like the way it pumps from the aux to the main - the aux empties, then when you run out on the lot you are out on the lot, wharas with the cruiser setup if things got tight you would be gambling with which tank is the emptiest(?), ie could run out on 1 and still have 10 litres in the other.

I think the 5 second or so run on the aux is to stop some unknowing person having stale fuel in the aus through ignorance - it slowly drains so has to be filled every now and then. I do not like this function. I agree the 35 (actual about 31 - 32 useable) is a bit on the small side, but it is a reliable 200km for me if I back off a bit - and haven't done too much stop/start driving to suck 5 litres or so of the top with that bloody 5 seconds.

An easy fix for the 5 seconds would be to find the relay for this 5 seconds and remove it with a suitable tool (crowbar), or re-wire it directly to the ffactory switch or a second switch, making the origional redundant.

As for capacity, I have considered the 70l replacement available from 4wd systems, possibly rerouting the exhaust and putting it on the passenger side and keeping the origional, fitting the 145litre replacement main, and/or fitting a 30 litre gas tank on the pass. side and going down the lpg fumigation road.

I'm not sure if the chev will like the gas, it is suposed to be a little better in direct injection diesels, but I think the chev will be very tolerant of what you throw at it. Please let me know if you try the disabling of the 5 second transfer at startup, and I will tell you how (if) I get around to trying it.

Cheers Andrew

PS I, like most others here, am very jealous of your conversion, mine being the powerhouse 2.8!

Muzzgit (WA) replied:

Bilbo, as stated above, I too like the setup of pumping from the aux tank into the main. I can understand your frustration though.

A good mate of mine has the diesel 80 series and he cannot get his head around the way the Nissan works, but I like it.

Member - BBB replied:

Bilbo

Ther is a GU long range tank in the Trader section of this site.

Might Help

BBB

Robin replied:

Hi Bilbo

For reasons as per Andrew and others I also prefer the current setup and have modified GQs to that way. Sure you can fit a 6 port valve in but your reliability is likely to go down.

Very little fuel is transferred on startup , and I think best policy is simply to
always fill up both tanks, on this basis the sub typically takes around 1 lt per 2 weeks.

Re-did my 4800 petrol GU to give 1000km+ range which meant adding , not the largest but the best rear main tank (OOT 145lt) to preserve ground clearance.

As part of this process I optimized the fuel sender and pickup which meant that I shifted the guage reading. My guage now reads full until the tank has used 20lt
and is much more precise at the lower end and will pick up fuel with under 2 lt in the main tank.

In the petrols the combined main tank fuel pump sender unit is pretty complex, and required breaking some spot welds and rewelding with everthing in place to extend the pick up point 1cm.

Just changing the way the sender arm works (and the resultant guage reading)
is easier, you just unbolt it and bend the sender arm (2 bends) such that the float
is closer to the bottom of the tank.

The sub tank sender unit can also be modded this way.

Robin Miller

Truckster (Vic) replied:

>>> The standard set up on the GU is that when you start up and the main tank is less than 3/4 full, the sub tank will AUTOMATICALLY pump (drain?) from the sub tank to the main tank for a period of 5 seconds - at every start up.

the reason it does this is to keep the pump lubed... Stop it and kill the pump. Is it that much of an issue?

Patrol22 replied:

Nissan must have put bigger subs in the later model GUs - my 2.8tdi GU 1998 has a 30ltr sub and Nissan kindly pointed with an erratum to the owner's manual to the effect disregard the 40ltrs sub we said we put in...it is only 30ltrs.

Fast_Patrol replied:

I believe it was a brown-davis part that allowed the patrol to be modded to work like a cruiser (based on memory from the patrol forum - I couldn't find any record of it in my own archives)

cheers
Andrew

Member - Matt M (ACT) replied:

What is the set up in the 100 series Cruiser? My petrol 80 operates the way most of you describe, ie sub tank transfers to the main at the push of a button and the engine only feeds from the main. I am a bit confused by the references to the Cruiser system.

I now understand why my sub tank goes down slowly as I hadn't realised that some is transferred on start up. Makes sense now I realise that it doesn't do it on the highway but only stop/start around town.

One of my concerns with this system though is what happens if the pump craps itself and I am left with 45 litres of fuel I was relying on? My only guess is that you would have to syphon from the sub tank into a jerry, then pour it into the main. Anyone had experience with this?

Cheers,

Matt.

Member -Dodger replied:

I ahve a replacement tank of 85ltr where the useless sub was and this too pumps to the main tank. It suits me ok and gives me a total of 175ltrs with a usable aamount of 160ltr due to the fact that I do not let the tanks run dry.
The reason for the sub pumping for 30sec is so that the pump is kept oiled and does not get gunk building up in it. These pumps are seneitive to rubbish in the fuel so I installed a cheap petrol filter before the sub pump and this collects the gunk. I change this filter (it costs about $5 at supercheap) every second major service 20 thow .
Works a treat.