Fuel continuously pumping before engine is started

[Mark-E]

Having recently bought a Series 3 2+2 I'm happily back in the world of 1970's cars that I originally learned my DIY mechanicing skills on when I was a teenager (in that case Austin 1100s). One thing the lowly 1100 had in common with the e-type is a Lucas electric fuel pump, and I remember how on turning the ignition on without starting the engine there would be a series of ticking noises until the fuel system was pressurised, after which the noises would stop (unless there was a fuel leak).

With my e-type the difference is that the ticking does not stop indicating that the fuel is continuously being pumped despite the engine being at rest and no obvious leaks being spotted. Is this normal, or does my car have a fault?

[PeterCrespin]

See manual section on fuel supply. The S3 has a recirculating system. Return valve might be iffy or it might all be OK, probably the latter.

[MarkE]

Mark, I've had my S3 for nearly 20 years, and every time I go to start it up I have a panic for a split second imagining petrol pouring out to a carburetor or two! I always imagine that there's no compression as well as the cranking noise with the V12 is so different to other cars.

You'll get used to it!

[spanish 2+2]

I had this problem on my series 2, purchased a new fuel-pump, not too expensive!

[AussieEtype]

Basically as Peter said.

When you turn the ignition on the pump will run quickly to build up pressure and when at full pressure the return valve opens allowing excess fuel to floa back to the tank.

From the drivers seat you will hear the pump running fast and then settle down to a regular click as excess fuel is pumped back to the tank.

On my Rover V8 (same carbs) there is no return valve so the pump just runs at full pressure when the ignition is on - so if the return valve is stuck open on the V12 you will hear the pump running all the time but should not be an issue.

I would be worried if I could not hear the pump.

Garry

[PeterCrespin]

I had this problem on my series 2, purchased a new fuel-pump, not too expensive!

Not relevant to S3 either. The sixes don't have a fuel return system.

[Alty Ian]

Mark

That is normal, stop worrying :D

Ian

[spanish 2+2]

I had this problem on my series 2, purchased a new fuel-pump, not too expensive!

Not relevant to S3 either. The sixes don't have a fuel return system.

You learn something everyday on this forum.

[Mark-E]

Thanks very much to you all for your helpful replies to my question.

I agree with Mark's comment on the cranking noise of the V12 it really does sound different, like there is no compression... until it fires and roars into life.

Thanks also to Peter - along with Philip Porter's Originality Guide, your Buyers Guide has been my bible for the last couple of years whilst researching S3s and finally buying mine (which I scored as a 94) :D

[PeterCrespin]

Thanks also to Peter ... your Buyers Guide has been my bible for the last couple of years whilst researching S3s and finally buying mine (which I scored as a 94) :D

Author of a bible? Hmm, I'll confess to occasional delusions of mediocrity, but that would be a stretch even for me. :-)

[Mark Gordon]

"
Author of a bible? Hmm, I'll confess to occasional delusions of mediocrity, but that would be a stretch even for me."

Hmm. Would that book be St. Peter's letter to the Coventryians?