Sediment in fuel system

[martinbrowning]

Hi everybody,
This could turn out to be the most stupid question of the week but.........
I have a near concours Sprint - the previous owner authorised a cheque book resto with Peter Day and Paul Matty. Because of it's condition, and the usual wet weather here, I only do at most 200 miles per annum. Wanted to drive it last weekend (sun had finally put in an appearance) but it would not start. It turned out to be a fuel supply problem as the float chambers were empty and no fuel was squirting out of the disconnected braided pump to carbs fuel line.
Further investigation revealed:
a very fine grained sediment on carb and fuel pump filters,
build up of sediment in the tank to pump fuel line.

Question is - where would this have come from? Is it a problem because I don't use the car enough?

Fuel is BP Ultimate with Millers VSPE additive.
I have also just ordered one of those really good alloy tanks from Andy Wiltshire in case the problem is within my steel tank

Any thoughts please?

Martin B

[Quart Meg Miles]

Fuel evaporates and a weak set of valves in the pump can let petrol drain back into the tank as well. I used to have to blow the petrol back up to the carbs after just two weeks until I fitted an electric pump by the tank (to control vaporisation due to the alcohol). Worth trying before you get the ali tank to see if the car runs with the filters as they are, if you haven't completely cleaned them aready. (By blow I mean into the filler hole, through a rag to keep it taste free).

[nomad]

I always store anything I am sure I won't be using for a while with a full tank of fuel. This greatly reduces condensation forming inside the tank. Never had a problem except for a basket case Jag that sat for several years with about a quarter tank.

Kurt.
26/3754

[martinbrowning]

Just an update to my initial post.... I replaced the original fuel tank with an Andy Wiltshire work of art, fitted a brand new AC glass bowl pump and blew through the fuel line with an air pump. Having put it all back together, she fired and ran.....Now, ten days later I tried to start it and although it spins well, refuses to start.

I'm fearing the worst that there is still sediment in the fuel line. I know that it is almost impossible(??) to replace the fuel line in the chassis without removing the body so thinking about disconnecting the line at both ends and pumping fuel through using a small electric pump.

Any thoughts please, or a better way of sorting the problem?

Martin

[rgh0]

check to see if your getting fuel all the way to the carb float bowls first. If not work backwards to find the problem.

if you have a new fuel take and have blown through the fuel line I would not think its a blockage in the line.

I would also check to make sure none of the new fitting are loose and the pump is not trying to suck air.

cheers
Rohan

[Quart Meg Miles]

.... I replaced the original fuel tank with an Andy Wiltshire work of art, fitted a brand new AC glass bowl pump and blew through the fuel line with an air pump. Having put it all back together, she fired and ran.....Now, ten days later I tried to start it and although it spins well, refuses to start.

Martin

As per my previous posting here, modern alcoholic fuel evaporates and I always had to blow into the fuel tank after leaving it for a couple of weeks, but it always worked after fewer days. It also didn't like getting hot and then having to run slowly in traffic.

Fitting a Facet PosiFlo pump (from Demon Tweeks) solved all those problems, but after a short stop in hot weather the pump works hard for about a minute even though the car starts fairly quickly. I don't think you've had a sediment problem, your car has got a drink problem with the alcohol.

Search for the thread "Fitting an electric fuel pump" and on page 4 near the top is Alex Black's fitting and at the very bottom my own version. (Ignore the comments I made in that posting as I didn't realise the pump was supposed to run all the time, but you can't really hear it except when pumping air!) Here's the pictures anyway.

Alex's

Meg's