"Old" Fuel Again

[david.g.chapman]

It seems that modern fuels last less and less time in a tank before going off.

I added 10 litres of 95 RON unleaded fuel to my +2 about 6 weeks ago, on top of about 5 litres of older fuel from last autumn. The car only fires now and again while cranking over, and the inevitable happens - the plugs foul up and the attempts to fire cease. I am confident that the engine is OK.

I suppose that conditions in a +2 tank with high levels of ventilation and only 15 litres of fuel mean that oxygen and moisture can get in and quickly degrade the fuel.

I even added some old POR15 fuel stabiliser 2 months ago but it did not help much - the bottle is about 12 years old, and I have just found out that similar products only last 2 years or so on the shelf once the bottle has been opened - I am sure POR15 is on the same boat.

Perceived wisdom is to brim the tank over winter and use fresh fuel stabiliser - the trouble is what if it doesnt work?

So I have bought a syphon pump to drain the tank and will mix the fuel with fresh in one of my modern cars, then refill with fresh fuel when I want to start the car.

Has anyone had a similar experience?

Dave Chapman.

[pereirac]

Hi Dave,
I started my car up for the first time after sitting in my garage just before christmas and it was fine (took a few goes though). I tend to stick to premium grades and brands, usually Shell V-Power in the hope that they have less ethanol than some other brands. It seems that ethanol level in fuel varies not only by brand but also by location. The same fuel may have different levels of ethanol depending on where you buy it..!!
What plugs are you using? I tend to use NGKBP6ES spark plugs which I have been told are slightly hotter than the BP7ES plugs I used to use...

Carl

[Grizzly]

I tend to run my car almost out of fuel before putting it away. Then when i want to use it again i do a service (Oil,Filter,Plugs etc don't change the fuel filter at that point leave it until you have run a tank of good fuel through first) put a gallon of fresh high octane fuel in the tank, remove carb float bowl cover and fill them with fresh fuel (Seems to run better on the dodgy fuel if the engine has a bit of heat in it)

Never had an issue.

[david.g.chapman]

I use NGKBP6ES as well. I have been running the engine slightly rich as I have had problems with burning exhaust valves in the past, although my cooling system keeps the water temperature below 90 degrees.

Having a Stromberg head and running unleaded fuel does not help with exhaust valve temps.

I shall be using better fuel in the future - Shell V-power is a good idea or any RON 97 perhaps.

I also agree about heating the engine a bit to help with poor volatility. its 14 degrees tomorrow in Writtle so I might give it another try on the old fuel.

I also carry a spare set of spark plugs with me in case this happens when I am away in the car. Having said that the engine is quite reliable on fresh fuel in the spring, summer and autumn, when I use the car nearly every week, and fill up every month.

Have fun out there,

Dave.

[gus]

Get some fresh gas and feed small amounts into the carbs to get the engine to fire

once there is a little heat in the engine it will fire from poor fuel

oh, and drive it, bad gas diluted with some good gas is pretty much bad gas, you have to burn it off.

[simonknee]

I started the car for the first time in 6+ months in January this year. I thought I might get "old" fuel problems as I have suffered this in the past. Nope, the Shell V Power I had left in it was just fine. It was not at it's peak no doubt but I didn't suffer any of the terrible stumbling that "old" fuel gives you.

That said I have not touched anything less than 97RON for a long time.

[david.g.chapman]

Thanks for all your replies.

I am up and running again. I think I had two problems - poor fuel volatility and an issue with my recently rebuilt AC delco fuel pump. I got the engine to fire after changing the spark plugs (which were wet with fuel) and cranking the engine again on no choke. The engine fired, ran for 20 seconds and then died on me. When I looked at the plugs again they were dry!

The glass bowl on the fuel pump was only 1/4 full. I am not sure if that is significant, so I decided to put 10 litres of fresh fuel in using my two 5 litre jerry cans. After another 30 seconds of fast cranking the engine fired and ran normally. I went straight to a garage and filled the tank with RON 97. I was surprised it took 35 litres, giving a total of 45 litres added.

So... perhaps the fuel I had put in last autumn had partly evaporated, and deteriorated at the same time. I estimate there was only a few litres left, so the fuel pump was having trouble pulling the fuel through as well.

Perhaps also the fuel was becoming gummy and making the pump valves and carb float valves stick?

In future, I will run the tank low again, this time with fresh fuel and check that the pump is OK.

Cheers,

Dave.

[prezoom]

I got an unexpected surprise a couple of weeks ago. My mother-in-law recently passed away at the ripe old age of 98, and had left a pristine 1982 Honda Accord, with only 34k miles. The car had not been drives in 3 years, but when she decided traffic was getting the best of her, she parked it. I filled the tank and added some Stabil. A new battery and a couple of shots of starter fluid and the car started right up. No misses, sputtering, just ran like it had just been shut off.

[The Veg]

Bloody hell, you guys have ethanol too? I thought it was just another stoopid Yank-thing. You have my deepest sympathies!

[TroonSprint]

Hi Veg, the situation in the UK is that we can have up to 5% ethanol in our fuel. Suppliers can add up to 5% without having to label the pump, so the buyer doesn't know if the fuel has 5% ethanol or not. Above that level the pump must be marked with E10, and all old car users will steer clear of that. There is currently no fuel in the UK with ethanol higher than 10%.

Personally speaking, when a third of the world is short of food, growing crops to make car fuel seems like madness to me. But what do I know?

Mike

[RogerFrench]

Here in Texas you cannot reasonably steer clear of 10% ethanol. Sure, you can buy aviation fuel at some local airports, and racing fuel, but the price is horrible and convenience nil.
However, neither my Europa TC nor Elan seem to care too much. In both cases I've replaced the flexible fuel lines with modern, just in case the doom and gloom stories were true, and I put Stabil in the tanks if they're left for any length of time.
Otherwise, nothing. I suspect there are those who, as with lead-free fuel, have a shipload of horror stories and would forecast the end of the world or worse, but it's not so in my experience.
Bah humbug!

[denicholls2]

and filled the tank with RON 97

Not so sure this is a great idea. At least on this side of the pond, higher octane fuel gets the higher octane from adding alcohol. Alcohol additives are the biggest quality issue with modern fuel.

Lead used to be the additive, but we all know what happened to that, or if you don't, they put it all in the Flint River in Michigan to keep better track of it and so the city government could feed it to school children. There are additives that don't deteriorate the overall fuel stability, but you're unlikely to find them at the pump unless you fill up next to Cessnas at the airport.

Fuel contamination in 6 months isn't overly likely. Although I've fretted a bit about it, my second car was last filled in that timeframe, with the cheapest stuff available. Started just fine yesterday.

In the U.S. at least, summer fuel is much better than winter fuel, which contains a lot more alcohol. My Prius sees a 5-10 mpg jump in either direction when what comes out of the pump changes in Spring and Fall.

[nomad]

David: I thought POR 15 was paint! Just what are you adding to your tank!

Mike: As one of the last of the full time farmers left in the US before big multinational's own it all I can give a bit of insight into ethanol in gasoline. First off, if we are growing the corn near break even, and we are, then discontinuing making alcohol from the "food" we are producing doesn't leave more for the world to eat. It only ensures that we would produce less because we, like everyone else in capitalism, would be forced to cut our losses or perish. Furthermore, what is removed from the corn in the distillation process is the starch. It is my understanding that the world is awash in starch and what is really lacking is protein.
Currently 34% of the US corn crop is used for alcohol production but only 17% is consumed in the process. The rest becomes a high protein livestock feed.
The number one reason to add alcohol is as an octane booster that replaces MTBE a carcinogenic petrol industry octane booster. Here in the midwest we can get any mix of alcohol we want to mix up at the pump and it is mighty handy for some of those old engines that had the heads milled a bit too far!

Kurt.

[The Veg]

In the U.S. at least, summer fuel is much better than winter fuel, which contains a lot more alcohol. My Prius sees a 5-10 mpg jump in either direction when what comes out of the pump changes in Spring and Fall.

What I would in theory gain in the summer I lose -plus some more- due to having to run the aircon at max all the time in my Mazda, thankfully the car is about as efficient as you can get without getting a Pious.

[david.g.chapman]

By POR 15 I mean the tank sealer they produce. POR 15 has become a generic term.

Having written that, I would not be surprised if it really is paint and the POR people have just re-branded it as it works as a tank sealer!

Just as a postscript, since I filled the tank up with 97 RON the car has started first time every time.

Dave.