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Old "new" petrol

Posted: Sun Apr 17, 2011 5:46 pm
by Ian Anderson
On Friday, I attempted to wake the Jupiter from it's winter slumber, in order to attend the North East sections "drive it " day at Whitby today (Sunday 17th April). It eventually fired up and ran on tickover for about 5 minutes getting more uneven all the time until it stopped and would not start. I cleaned out both carb float chambers, although they seemed OK anyway, and removed and cleaned the plugs which were black. I started it again and tried a blast up the road but it cut out again. The car was behaving as if the chokes were stuck on, though I could not see any smoke from the exhaust, and the plugs were sooted up again. I rang round various people looking for suggestions (thank-you all for your help). Mike Smailes mentioned the age of the fuel but I thought it would only be about 7 months old. I obtained a 25litre plastic oil drum from my local garage and started to pump the tank dry using the SU fuel pump. The tank ran dry after less than a pint, and the fuel was the colour of pale ale. My fuel gauge only works with more than 3 gallons in the tank (SA sender in an SC tank I think), but I am sure there was more than a gallon in when it was last run in September. Presumably the fuel had evaporated, and what remained was very low octane. Fresh fuel cured the problem, and I have just returned from a pleasant lunch in Whitby. I have always left petrol in the car over Winter intending to start the engine periodically, but this Winter's weather made a trip down to the garage an unattractive idea. If the make up of modern petrol has changed, should we be draining our tanks, or has anybody tried petrol preserver additive as one of my farming neighbours puts in his petrol stand-by generator?

Ian Anderson

Re: Old "new" petrol

Posted: Sun Apr 17, 2011 8:59 pm
by Keith Andrews
Presumably the fuel had evaporated, and what remained was very low octane.
Yes..but consider that these engines where made to run on very low octane..that is not the issue...
The blend of sovents evaporated leaves a lot of detergents and additives and basically the crap part of the pterol

This subject was discussed about a week or so ago.

Re: Old "new" petrol

Posted: Sun Apr 17, 2011 10:02 pm
by Robin Fairservice
I put fuel stabiliser in any fuel that will be staying around for more than2 or 3 months. That seems to be common practice around here (Prince George, British Columbia).

Re: Old "new" petrol

Posted: Mon Apr 18, 2011 5:55 am
by Keith Andrews
That seems to be common practice around here (Prince George, British Columbia).
Hmm I think you find States Side and Canada, and you have a muscle car/ camaro... driven only in summer months, the general practice is to run the tank low, store the car, then get fresh fuel , at least 1/2 fill the tank with fresh gas, top up then drive to the gas station and fill right up....Road trip time.
Additives and 'stablerisers' dont work to stop factional evaporation....

Re: Old "new" petrol

Posted: Mon Apr 18, 2011 11:07 am
by Amy
Ian we had a similar problem when trying to get my SC started a few weeks ago. There was plenty in the tank, but it had sat since November. He turned over but just wouldn't catch - Easy Start cured it and I went down and put plenty of fresh fuel in the tank and he's been fine since.

I think what I'll be doing in future is making sure there's not much fuel in the tank if I know the car's going to be in the garage for a while, then adding a fresh can of fuel when I do want to start him.

Amy.