Fuel Problems


This month I thought we would take a look at fuel problems, which many of us Austin Seven enthusiasts will be able to relate to and appear to be on the increase. With ever rising raft of bureaucracy within the EU regarding the percentage of bio-fuel mix to unleaded, which thankfully has largely escaped us here in the UK for now, but I wonder for how much longer. Those members that went on the Viking Tour will remember the higher than average percentage of bio-fuel added to unleaded in Denmark as much as 30% plus and the running problems that caused. Most of our Austin Sevens have at some time had blocked jets caused by petroleum filtration sands or rusting fuel tanks. They are fairly easy to fix by cleaning out the carburettor bowl and jets, unless somebody has decided to use “Slosh Sealant” in the tank in an attempt to overcome rust flaking.  One of the major contributing factors is the corrosive chemical additives used in unleaded, bio-fuels and the other is poor preparation before applying tank sealants, most of which were developed long before bio-fuel came onto the market. There is no short cut, cleaning fuel tanks can be dangerous, messy and there’s no guarantee after all your hard work that you have fixed the problem you were trying desperately to fix.

It’s not that easy to clean out bio-fuel (waxing) which blocks fuel pipes jets and in the worst case it causes some gaskets and cork seals and fuel pipes to disintegrate. If you have not come across this before, then the simple way to describe it is by referring to the old fashioned liquid wax table lamps, globules of wax moving with the heat of the lamp. In our case it’s moving around in the fuel tank, the longer the vehicle is left unused the greater the risk, you could minimize the risk by using the better known branded petroleum retailers. Not wishing to sound totally negative but this is some technology our little Austin Sevens could well do without and have yet to see any measurable environmental benefits to the contrary, bio-fuel chemical additives are more corrosive and toxic, one for ongoing debate!

Spare a thought for the gentleman I met in Dunmow the other day. He had the misfortune of having his Aston Martin DB4 recovered back to the UK from a tour in Spain on only the second day, having just spent many thousands of pounds on a complete mechanical restoration. Needless to say he was less than pleased, but more was to follow the carburettors having just been totally restored by an SU specialist needed all the cork seals and gaskets replaced plus the entire fuel pipe and the SU fuel pump, the fuel tank had to be removed and chemically cleaned. So be warned when driving on the continent, some retailers seem to use whatever they can lay their hands on and the percentage of bio additive could be as much as 50% in some countries, you have been warned.

A7 Fuel Pump

Download SU Fuel Pump Article  Fuel Pump




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