Outer Limits 4x4 Board

G'day all just bought a 98 GU patrol its got an after market ATX turbo DX model and the sub tank light is always on. now ive been told to disconnect the battery and that works but it comes back on. now i also have been told i probably was affected when i had an alarm put on it.

my question is how can i get my sub tank to work? cause i nearly ran out of fuel last week and i couldnt switch to the sub tank.

any help is always helpful
thanks in advanced
Matty

do you have a turbo timer?


also pull the sender unit out of the main tank and check it is all ok.

if the sender isnt sending the right voltage the computer will shutdown the use of the subtank transfer pump

cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

familybus wrote:cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

ours is doing this aswell so would be very interested if anyone has any ideas on whats going on

familybus wrote:cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

The subtank will pump a small amount of fuel (not sure exactly how much but a litre or 2) into the main tank everytime you start the car.

mwhitfield_2000 wrote:G'day all just bought a 98 GU patrol its got an after market ATX turbo DX model and the sub tank light is always on. now ive been told to disconnect the battery and that works but it comes back on. now i also have been told i probably was affected when i had an alarm put on it.

my question is how can i get my sub tank to work? cause i nearly ran out of fuel last week and i couldnt switch to the sub tank.

any help is always helpful
thanks in advanced
Matty

It would be a turbo timer problem. After switching the car off and turbo timer goes through its paces, the next time you start the car the sub tank light will come on. The problems is that some electronics are disabled but others are on when the timer kicks in which puts something into limp mode or something. To fix I have heard you need a balast resistor connected across a couple of wires. Mine does it but I can't be bothered to investigate.

mwhitfield_2000 wrote:G'day all just bought a 98 GU patrol its got an after market ATX turbo DX model and the sub tank light is always on. now ive been told to disconnect the battery and that works but it comes back on. now i also have been told i probably was affected when i had an alarm put on it.

my question is how can i get my sub tank to work? cause i nearly ran out of fuel last week and i couldnt switch to the sub tank.

any help is always helpful
thanks in advanced
Matty

It would be a turbo timer problem. After switching the car off and turbo timer goes through its paces, the next time you start the car the sub tank light will come on. The problems is that some electronics are disabled but others are on when the timer kicks in which puts something into limp mode or something. To fix I have heard you need a balast resistor connected across a couple of wires. Mine does it but I can't be bothered to investigate.

Grungle wrote:

familybus wrote:cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

The subtank will pump a small amount of fuel (not sure exactly how much but a litre or 2) into the main tank everytime you start the car.

yep i knew it did that but it seems to be using more than that

Could be a venting issue in the main tank. Only way to equalise the pressure is by sucking fuel from the subtank.

do you have a turbo timer?

yes i do but its bulit into the alarm system

I will check the sender unit this weekend

does any one know the voltage it should for the sub tank

hey roly what vehicle you got now?

as above it'll be your turbo timer putting it into limp mode


arb sell a seperate timer for the gu with sub tank for this reason.

i have ordered a SR5 Dual Cab Hilux

3 month wait

muduppig wrote:

Grungle wrote:

familybus wrote:cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

The subtank will pump a small amount of fuel (not sure exactly how much but a litre or 2) into the main tank everytime you start the car.

yep i knew it did that but it seems to be using more than that

WELL THAT CAN'T BE, IF IT USING MORE THAN THAT IT LEAKING SOMEWHERE, ASSUMING IF ONE OR TWO LITRES EVERY TIME YOU START (WHICH I DOUBT) IT WOULD ONLY TAKE 15 - 30 STARTS TO DRAIN SUB TANK (30L) I WAS UNDER THE IMPRESSION THE SUBTANK PUMPS FUEL FOR 5 SECONDS EVERY TIMES YOU START.

HARMZ wrote:

muduppig wrote:

Grungle wrote:

familybus wrote:cool! i just bought a 98 gu aswell and i have the oppisite prob, im trying to run only the main tank to see how many k,s i can get and it wont work the subtank seems to be draining into the main tank somehow!

The subtank will pump a small amount of fuel (not sure exactly how much but a litre or 2) into the main tank everytime you start the car.

yep i knew it did that but it seems to be using more than that

WELL THAT CAN'T BE, IF IT USING MORE THAN THAT IT LEAKING SOMEWHERE, ASSUMING IF ONE OR TWO LITRES EVERY TIME YOU START (WHICH I DOUBT) IT WOULD ONLY TAKE 15 - 30 STARTS TO DRAIN SUB TANK (30L) I WAS UNDER THE IMPRESSION THE SUBTANK PUMPS FUEL FOR 5 SECONDS EVERY TIMES YOU START.

no its not leaking i was stating that i knew that it pumped some over i woulnnt know if its 50ml or 2000ml but seems to be going down as the main tank does seems strange

by the way stop bloody yelling

yeh! stop yelling!
mine definatly is running down as the main tank is runnin down and i dont have timer or nuffin mines all standard!

Hi all,
This may or may not help.
I had probs when I replaced mu GU sub tank with an aftermarket 85ltr tank.
Pump over problems occured too numerous to mention.
Fix was a combination of,
1. Disconnect the batteries via the negative terminals and leave disconnected for at least 5 minutes then reconnect this resets the fuel computer.
2. Fit an inline fuel filter ( just the $5 type petrolit works for diesel as well) on the pickup side of the transfer pump found under the vehicle attached to the centre cross member.
3. Add an extra earth wire from this pump to the chasis and also an extra earth from tank to chasis.
4. Fit an additional earth from chasis to body.

None of this is hard or rocket science just time consuming.

does anyone have a manual with wiring diagram of the fuel computer that I could take a look at?