ive been working on a ford spectron van and its running now albeit roughly and stalls aftre a few seconds of running?

i've had some petrol in a car for 10 months now and its been sitting could that be causing it to run rough and stall all the time?
marcel

I used to have a few bikes that I had sitting around for long periods while I restored them, I had to have the tanks full all the time to keep the rust out.
When I wanted to start them, I had to drain the tank, pull the float bowls and give them a blow out, put the fresh stuff in and I also had to use FRESH PLUGS, if I tried to start them with the old plugs, they either would not go or would run rough and sometimes cut out altogether.

Rob......

Marcel, we get that at work alot with dual fuel cars that run on gas most of the time. The petrol can sit for a few months before its used and causes the problems you describe.
Try some new fuel, and use your old fuel for washing parts.
Graham

Apparently shelf life of fuel now is a couple of weeks now before it starts to go off, a guy I work with that has a fuel injected Honda which was at a pnel beaters for a month had the problem yesterday- ran terrible with revs fluctuating all the time- filled the tank & 15ks later no problem

Shelf life of a couple of weeks is not technically correct (unless you store it in an open container).

The specification for fuel varies from summer to winter (and in some areas, even in between). Its all got to do with making sure that the fuel evaporates in your carby, and not in the fuel tank or fuel lines. The technical term is RVP - Reid Vapour Pressure.

This is why if you buy fuel in summer, and try to start your car in winter, it may flood very easily and have difficulties starting - the fuel has a high RVP, and is basically not warm enough to vapourise. Likewise if you buy fuel in winter and try to use it in summer, your car will be much more likely to vapour lock, due to the lower RVP spec in winter.

This is the same the world over.

The other reason that fuel goes 'stale' is that the lighter components (petrol is not simply one molecule of hydrocarbon - its a blend over a range of molecules - for those who remember high school chemistry, its C4 through to about C9), which are blended into the fuel to raise its RVP, will evaporate from the tank unless it is sealed, thus lowering the RVP and altering other aspects of the fuel (like the RON and MON), and altering the way it behaves in your car.

Cheers,

Doug Sweetman

Yeah the fuel does go off.

Like Robo said, you also need fresh spark plugs. The reason is that over time the deposits on the plugs absorb water from the air, and then they don't spark properly. Scrubbing old plugs with a toothbrush dipped in petrol works well enough to get a lawnmower/whipper snipper started, but for a vehicle it's worth forking out a few bucks for brand new plugs.

thanks for that I drained the tank and refilled with fresh fuel and runs much better now thankyou
marcel