Stale petrol......

[gromit]

I've had a problem with a couple of the Land Rovers that stand outside in the open. Petrol smelt 'stale' plus I had the fuel pumps stop operating, take the pump apart and it seemed the valves had stuck.
Both vehicles would run OK but took a bit of effort to get started,

Checked the dipstick on the military IIa fuel tank and the end was covered in sludge and the brass was being eroded. The fuel had gone off and was leaving a lovely brown sludge everywhere.

Dropped the tank and took the picture below through the level sensor opening.

https://www.aulro.com/afvb/images/imported/2015/07/1194.jpg (http://s1245.photobucket.com/user/cradley/media/Series%202a%20GS/DSCN3549_zpsb0xqlhyv.jpg.html)


Looks like it needs a bit of work to de-rust and clean the inside before sealing it to stop further rusting.

Rigged up a temporary tank, dropped the sedimenter bowl and cleaned it then flushed the fuel system through. Starts & runs a lot better on fresh fuel, funny that......

Temporary tank will stay for a while while.

https://www.aulro.com/afvb/images/imported/2017/05/471.jpg (http://s1245.photobucket.com/user/cradley/media/Series%202a%20GS/DSCN3537_zpslzmmoaz1.jpg.html)



Colin

[p38arover]

Looks like it needs a bit of work to de-rust and clean the inside before sealing it to stop further rusting.

I derusted a tank with molasses and water solution.

[gromit]

I derusted a tank with molasses and water solution.

A lot of the brown stuff at the bottom isn't rust, I have to find something to dissolve that first.

With molasses I read somewhere that having something half in caused problems with rusting at the barrier between the molasses & the air. Did you brim the tank with molasses ?

Colin

[p38arover]

Yes, I did write about the interface problem and I did fill my tank to the brim.

I haven't tried tank sealers but a few blokes have used them for their motorbike tanks which seem to be very vulnerable to rust.

[Don 130]

These days the petrol needs a fuel stabiliser if being left for any extended period. The stuff is not expensive.
Don

[gromit]

These days the petrol needs a fuel stabiliser if being left for any extended period. The stuff is not expensive.
Don

I understand it only stabilises for up to a year.

Probably better if your not yet using the vehicle to either drain completely or keep the fuel level low and drain it out annually and replace with fresh.

I added fresh to the old fuel (no idea how long it had been in there).

Once the tank is cleaned up & coated I might stay with the temporary tank until I get the vehicle back on the road.


Colin

[JDNSW]

The extent of the stale fuel problem is largely a function of the humidity. Not much of a problem inland, and the more humid the worse it gets. Mainly due to bacterial action at the interface between the fuel and water that condenses with changes of temperature (The bigger the daily change in temperature and the higher the humidity, the more condensation you get.)

The solution is to either drain the fuel completely from the tank (and drain condensation before putting it back into service) or alternatively fill the tank completely before the vehicle is stored, which will largely prevent condensation. And if possible avoid using fuel with ethanol in it, as this makes the water miscible with condensed water, so that bacterial action can take place anyway. A fuel stabiliser will help, but how long it lasts will depend on how much condensation exists, so use it in addition to the above precautions.

John

[Blknight.aus]

the best thing you can do is use the fuel.

fit a facet pump and an openable stop cock to the fuel line. when you need to do the lawns open the cock, fit a hose and turn on the pump then fill the mower.

when you're done (one a month or si go for a drive in the vehicle as a "maintenance run" and top the tank off.

more fuel with less ullage space lasts longer than a partially filled tank.

[gromit]

Can't afford to have loads of Land Rovers sitting around with full fuel tanks so I think I might drop the contents, leave the tank vented and switch to a temporary tank when I want to move it around the property.
Once it gets back on the road I can re-connect the tank.


Colin

[crackers]

You'll find that 95 octane fuel lasts better than 91 but yeah, stale fuel is still an issue.

[gromit]

Seems life is about 6 months but that's in a sealed container.
Octane rating is dropping after a few weeks.

AutoSpeed - The Life of Fuel (http://www.autospeed.com/cms/article.html?&A=112237)

Not sure that octane rating has any effect. Interesting that some brands were felt to be better for storage.


Colin

[Blknight.aus]

Can't afford to have loads of Land Rovers sitting around with full fuel tanks so I think I might drop the contents, leave the tank vented and switch to a temporary tank when I want to move it around the property.
Once it gets back on the road I can re-connect the tank.


Colin

In that case the best thing you can do is drain and air dry the tank then split the pick up line with a union fittig.

grab an outboard tank and mod a primer line to fit the union or braize a pick up onto a jerry pourig neck and use that for your shuttlig and routine runups.

[gromit]

Got a reply from BP Technical Dept.

The attached provided information of fuel storage life, the copper in the carburettors and lines reacts with sulphur in the petrol to form the gums so use a low sulphur petrol like 95 octane or 98 octane.

A fuel conditioner such as used for outboards can be used and then add fresh fuel before you use the engine.

For cleaning out the gums a mix of Toluene, acetone and methanol or methylated spirits works, the ratio is 40% toluene with 30% acetone and 30% methanol.


I've been trying Acetone with limited success, looks like I need to add some Toluene & metho.
The fuel pickup was almost completely blocked with resin/gum, just need to clean the resin from the tank, de-rust & seal.....


Colin

[mick88]

The fuel issue is annoying and when it turns to varnish like gum in the carby etc it is a pain to clean out. Recently had this happen to one of our Honda stationary engines that had been sitting for some time. Interestingly a two stroke outboard that had been sitting for several years fired straight up when I tried it. Maybe there is something in two stroke oil that preserves the fuel and prevents gumming! Cheers, Mick.

[gromit]

Picked up some Toluene today so I'll have to make a brew and try it.
I'm guessing but it's probably 'carby cleaner' I'm making but in a larger quantity (and cheaper).

Mick, interesting with the two stroke situation......


Checked another couple of vehicles and if they don't get a run soon I'll be draining the fuel system and using a plastic bottle for the occasional run up.



Colin

[dromader driver]

If I have fuel sitting around eg for the generator I try to buy 98. Based on seasonal experience where the mowers don't get used for around 6 months. :cool: