Stale Fuel Prevention.

[Daviewonder 533 3 Cars]

Having several cars that stand for several years at a time I find stale fuel to be a problem. Does anyone know of any additive that actually works to prevent this?

 

I've come across these on eBay. Anyone have any experience, or are they just a con?

 

Link

[welshpug 1,626]

Never found old fuel to be a problem, just leave it empty or low if its going to be sat.

[Ryan 99]

You're supposed to leave the tank full. Fuel goes stale because the various compounds evaporate out. A full tank means there's less air in the tank for them to evaporate into.

 

You can buy fuel stabilisers that you pour into the tank, but I'm not sure how well they work. Pellets that you drop into the tank definitely won't.

[roccorich 16]

Yeh I recon those magic diamonds are as useful as those magnets you put on your fuel lines to improve fuel economy.

[Hheppy 9 1 Cars]

I was told that Shell Nitro or eqivalent doesn't go off as quickly as the normal unleaded, I have used that in my pug recently, the test will be in a couple of months I guess.

 

Something to do with the Nitro having less ethanol content.

 

We shall see.

[Batfink 201]

why dont you park the car up with minimum fuel, then when you want to drive the vehicle fill the tank up with new fuel

[TT205 42]

Just pour a new can of petrol in and it should be fine

 

If it is that the old petrol loses octane when stood? then you could add Millers CVL when you want to get it going again

[Ryan 99]

It's not that it loses octane as such, it's more that it just goes bad and becomes harder to ignite, which makes the car hard to start.

[welshpug 1,626]

might be the case for a race car on high compression, or something old running carbs, but a 205 on jetronic or motronic will run just fine.

[DamirGTI 327]

Indeed , stale fuel is notorious for choking up carburetors .. EFI engine really shouldn't have issues caused by stale fuel , at least not up to the point of moderate storage . If it where way too old might be a little harder to start initially , but once started add some fresh fuel to mix with old and it'll be fine later .

 

Been working on outboard engines (still do during the summer season) , and on these , stale fuel is always an problem . Especially if the motor is stood stored "winterized" without being shut down with an mixture of fuel and fuel stabilizer .

 

If you like , pour in some stabilizer (marine stuff works really well , myself i've been using "Quicksilver" stuff ..) .. needs just small amount of stabilizer per tank .. but as said , it isn't necessary for EFI engine .

 

D

[jackherer 543]

There is definitely a point where fuel is so old an Mi16 on motronic wont run, but as said above a fivers worth of fuel and it fired straight up, nothing was blocked.

[welshpug 1,626]

What point would you say that is though?

 

Two and a half years without issue is my experience!

[jackherer 543]

I can't be sure as we bought the car from Atomic Jon on here years ago and it had been standing for an indeterminate length of time as a non runner. I put an Mi16 in and it wouldn't run and after a while of trying things we realised we had no idea of the history so we put a bit of fuel in and it fired right up.

[DamirGTI 327]

I took an full tank of old 98 Ron leaded fuel (from an Peugeot 404 ! ) which was standing at least 8 years .. but then , may have been easily 10-13 years or even more by the owners input about when the car was last time used since it was parked in the garage for storage .. The fact that the running gear was completely sized makes me think it was more than 10 years in the garage for sure ..

 

Anyway , filled up the fuel inside EFI car (though there was some fresh fuel inside for the start) was starting/running fine despite slight pinging/detonating on full load so we just backed off the timing a few deg. for the time until the tank was empty enough for filling it up with fresh fuel .

 

D

[Daviewonder 533 3 Cars]

Thanks for the advice guys. I won't be buying one of those eBay gimmicks then.

 

I wonder if my problem is from parking them up without much fuel in them? I have this off fuel issue quite a lot.

 

My 106 gti was stood up for about a year and when I came to start it it wouldn't run properly until I whacked some fresh fuel in. My 2.0 turbo conversion wouldn't run when I first put the engine in due to the fuel being nearly 3 years old. I drained it and replaced it with fresh and it fired straight up.

 

This time it's my 1.6 gti. It has about an eighth of a tank but has been stood for almost 3 years. I've whacked 2 jerrycans (5 litre ones) of unleaded into it on top of the old but the car is misfiring a bit when revved. When I spray a mist of starting fluid around the air intake the misfire goes away.

 

I wonder if the stale fuel could be more of an issue depending if the timing wasn't quite right?

[roccorich 16]

If a car has a metal tank you are better off leaving it full to help stop it rusting on the inside

 

If its plastic your probably better leaving it pretty empty then filling up when you start driving again, Id recommend using shell v power for the first couple of tankfulls if you dont use it normally anyway as its got good cleaning stuff in it.

[DamirGTI 327]

 

I wonder if the stale fuel could be more of an issue depending if the timing wasn't quite right?

 

Maybe .. cod be also "type/blend" of the fuel which was left filled inside the tank , all refineries are subjected by law for changing/switching fuel evaporation and igniting temp. characteristic for particular season time thus making different separate blends - summer blend and winter blend .. so one of the two blends might be more prone to degrading during the years , and the actual season time when you try to start the engine with such fuel may manifest harder/easier to ignite .

 

D

Edited October 21, 2013 by DamirGTI