GU Sub tank problems

My 4.5 petrol GU used to pump a bit from the sub tank to the main every time it started. I could never work out why my tank was draining. I believe it is set up like that so the reserve fuel does not go stale.

Willem,

Does the sub-tank drain while the car is stationary? If so, then he has a problem - but,,,,,,,,,,,

Or does it drain when it's running?

The standard GU set up is that once the Main Tank gets down to less than 3/4 full then the 'tank-logic' will allow a small amount of fuel to go from the sub to the main each time the vehicle starts up.

It doesn't take long for the sub tank to disappear if yer doing stop/start runs often.

I don't like the set-up, but it's "'standard Nissan"

Bilbo

Willem,

I have a 2000 GU 4.2 diesel that has only started to drain the sub into the main of its own accord. For the first 5 years I had to manually press the sub tank button.

Regrads
Ross

If its draining in one week it might be worth while to check if the solenoid is working.

I have heard of the coil burning out which could lock into a half open, quarter open etc position.

Cheers

We have a GU 1999 model 4.2 and yes it does empty a little out of the sub tank each time you start it but it takes a lot longer than has been mentioned in your post to empty. We had the oposite problem with ours, after we got off of the CSR. (a couple of years ago) was heading to Fitzroy Crossing after leaving Halls Creek thinking that we had plenty of fuel, pressed sub-tank switch, half hour later sub tank still full, oops!! finished up having to drain subtank into bucket and putting it into the main tank that way, problem was the pump from the subtank. Hundreds of $$$$$$to replace new but our mechanic sourced a good second hand one for half the price and is still going strong.

Cheers

Deanna

Hi Willem

I own 1998 GU 2.8lt Tdi. when you first start the patrol the sub tank drains around 7-9 secs worth of diesel into the main tank. Unless he his starting the patrol a lot within the week this shouldn't account for the sub tank draining in a week. not sure if you know this already but it may give him some answers.
when you find out the exact problem can you post it on the forum because i would also like to know why.

Thanks