Fuel ?

Submitted: Sunday, Jul 03, 2005 at 10:02
ThreadID: 24383 Views:1940 Replies:6 FollowUps:9
This Thread has been Archived
We keep a pretty good eye on our fuel, we have a long range tank 145L and have also fitted a larger reserve tank 80 L was the first fill after fitting that was over 12 months ago now and since then we have only been able to fill the tank with 69-70 Litres, now i understand that the tank will not pump all the fuel out and requires some to be left in the tank, however after just doing a review of our log i recall last year when we crossed into WA and "bingo" all of a sudden each fill we did we got 79 L into that little old tank of course we do not track our main tank as closely because we never run the main tank to empty, as a note we did 16,000 mainly all towing 60/40 black top/dirt and got 3.92k/Litre we have a 4.8 Gu TI Patrol weighing in at 3.5Tonne and tow an off-road CT of 1.5 Tonne.
Anyone got any ideas
Back Expand Un-Read 0 Moderator

Reply By: Penguin (NSW) - Sunday, Jul 03, 2005 at 12:31

Sunday, Jul 03, 2005 at 12:31
The only thing I can suggest is that the pickup in the tank has moved and is now able to reach a bit deeper.

AnswerID: 118622

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 13:01

Sunday, Jul 03, 2005 at 13:01
Hi Penguin, i forgot to mentioed as soon as i crossed back to NT " Alice Springs" it went back to filling to only 69 and has been the same in all other states as well as New Zealand i thougt that it might have been heat as the truck is mainly in New Zealand in the summer but have had some late hot weather in Qld since we have been home and still 69 not sure what they put in it in WA.
Puzzled
0
FollowupID: 373781

Reply By: desert - Sunday, Jul 03, 2005 at 13:21

Sunday, Jul 03, 2005 at 13:21
It depends on how much stop-starting you are doing. The Patrol runs it's fuel from the rear tank to the engine. When you use the sub-tank switch it simply pumps fuel from sub to main. In order to prevent the sub pump from drying out, Nissan have wired the controller so that each time the vehicle is started the sub-fuel pump will pump fuel for 10 seconds, whether or not you have pushed in the switch. At a guess I think it would shift about 250ml in 10 seconds, so this fuel is always moved to the main tank. If you are erroniously doing fuel calculations based only on what you put in the sub-tank, then it will, of course, be up thebleep. You must do your fuel sums by filling both tanks and using that amount for your calculations.
AnswerID: 118625

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 13:38

Sunday, Jul 03, 2005 at 13:38
Hi Desert,
Yes i am aware of that and do fill both tanks however one can never really tell how much you have left in the main tank because of what you have said, the point is that when i fill my reserve which is not the standard reserve as issued by nissan but one made by loneranger as i said when it was first filled it took 80 Litres and i have never been able to get 80 back into it and i accept that it keeps some in the tank after it shows emty and will not pump any more i have tried to pump down hill uphill you name it, i am not questioning my calculations or the the reading at the pumps, however each time i filled up in WA it takes 89 L now i think that is strange, could it be that WA measurs are different to the reat of Australia and New Zealand, i wonder what would happed if you never filled the sub tank. When we fill we always fill both tanks and take a note of what went into the reserve i could understand if it was just the odd pump, like once in NZ it took 91 Litres when i went to query it with the manager at the station it nearly caused a war.
0
FollowupID: 373785

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 13:42

Sunday, Jul 03, 2005 at 13:42
Sorry desert,
Should have read 70 Litres for WA and 60 Litres for the reat of Australia
0
FollowupID: 373787

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 13:44

Sunday, Jul 03, 2005 at 13:44
I'll get this right in a minute 79 Litres for WA and 69 Litres for the reat of Australia,
Tme for a power nap
0
FollowupID: 373788

Reply By: Exploder - Sunday, Jul 03, 2005 at 14:55

Sunday, Jul 03, 2005 at 14:55
Try just running it till the sub tank is dry and the engine stops (it’s a petrol so it won’t do any damage). Then just run of the main tank, then in the morning when it is is cool fill it up to the brim and see how much you get in.

There will still be a few Litres of unusable fuel left in the tank and from there you should be able to diagnose what is going on.

Why you are getting more In WA I don’t know maybe there was higher atmospheric –pressure when you were overhear and that compressed the fuel in the tank allowing you to pump more in. (It’s a long shot but hay it’s a theory non the less)
AnswerID: 118634

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 16:08

Sunday, Jul 03, 2005 at 16:08
I dont think i can can i ? as in the Patrol you only ever run of the main tank and the sub emtys to the main tank. I thought that it was somthing to do with the hot weather and expansion as well but after the last trip to NZ we even filled up 2 degrees one day and got 69 so i just dont know what it was.
Atmosheric - pressure well now thats a thought would that have anything to do with it being dry and not humid.
Regards
10 Para
0
FollowupID: 373805

Follow Up By: Exploder - Sunday, Jul 03, 2005 at 17:38

Sunday, Jul 03, 2005 at 17:38
Yes true the patrol’s do draw from the main tank I thought because you put an aftermarket tank on it may have been set up to draw from either of the tank’s.

Generally WA has higher atmospheric pressure than the east (I think). The higher you go the less pressure and if you have a low-pressure system and you are at altitude alpine areas in New Zealand for example it is possible it could have an effect. 10Ltrs deferens compared to WA very unlikely.

Perhaps the fuel gage is playing games. Try just forcing 80Ltrs into the empty sub tank see how much goes in before it start’s coming out the filler hole.

If you fill up early in the morning when it is still cold you will get the same amount of Litres but you will get more fuel as the specific gravity of fuel is at it’s lowest .79 from memory. Sorry didn’t explain that to well
0
FollowupID: 373809

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 17:54

Sunday, Jul 03, 2005 at 17:54
Phew that one has gone right over my head as well, and i have had my nap, tried that seceral times fill slow shake truck fill slow again still only 69 i am not that worried about the 69 i can accept that i have 10L in the tank that i can't run i just can't get my head around the WA thing but have to take a short cut to the Alice this year via Broome to find out for surem glad i had the handbrake with or she would have thorugt i was ready for the chair and telly.
Thanks for that
10 para
0
FollowupID: 373811

Reply By: Member - Roachie (SA) - Sunday, Jul 03, 2005 at 17:11

Sunday, Jul 03, 2005 at 17:11
What about draining the sub tank using the drain plug (once you've pumped the majority of contents to main tank of course). That way, you should be able to ascertain how much fuel is still in the tank after you've pumped it all over. Still won't explain why you were able to get 79 in when you were in WA, but at least you'll know that if it's only taking 69 at most servo's and you find there is 11 litres still in it after you've pumped; then it's a case of the pump cutting out too early....you may tehn be able to adjust the pump pick-up so you get more of the fuel to pump across.
Hope this makes sense.
Roachie
AnswerID: 118644

Follow Up By: 10 Para (Qld) - Sunday, Jul 03, 2005 at 17:21

Sunday, Jul 03, 2005 at 17:21
Thanks Roachie,
I can see you had a power nap this afternoon, great idea its going in for its 60th tommow so i will Motsons to do that in the morning will let you know what happens, i still think it could be them guy's at the WA boarder though.
Regards
10 Para
0
FollowupID: 373808

Reply By: Blaze - Sunday, Jul 03, 2005 at 22:19

Sunday, Jul 03, 2005 at 22:19
All I can add to this, is while we were away lately in WA and NT, a mates patrol which has a 30ltr sub tank varied from 30ltrs to 39ltrs, which we all know is impossible, but it sure was interesting, noticing every time it took extra ltr's was at a 4 cent off discount fuel outlet, seems you get the ltr's cheaper but need more of them Hmmmmmmmmmm.
AnswerID: 118694

Follow Up By: 10 Para (Qld) - Monday, Jul 04, 2005 at 11:51

Monday, Jul 04, 2005 at 11:51
Thank god i am not going mad.
0
FollowupID: 373930

Reply By: Truckster (Vic) - Sunday, Jul 03, 2005 at 22:21

Sunday, Jul 03, 2005 at 22:21
The fuel pumps were wrong....
If it was only in 1 or 2 places you magically got more in the tank, then the pixies left, and you went back to normal....
AnswerID: 118695

Sponsored Links

Popular Products (14)