PUMPING PETROL ON STARTING

[tonycharente]

Hello everyone,
I have a RHD 1969 ELAN S4 SE FHC on Stromberg carbs. If I leave the car for a week or more between using it, I have to churn the engine for ages before it will start, and I think this because I am having to pump petrol through because (presumably) the carbs are empty. I think this because once I've churned it for a while it starts without fail and also because if I only leave it for a few days it starts instantly without churning, just like a modern car. There is no sign of any petrol leaks. The petrol pump has been replaced, and once started it runs perfectly with no signs of fuel starvation.

My questions:
(1) Is this "normal" - on Strombergs they're all like that?

(2) Should there be any kind of one-way valve in the fuel line?

(3) Any other suggestions, please?

Many thanks,
Tony

[cliveyboy]

Tony
The carbs emptying of fuel over time is very common on Webers and Dellortos. Strombergs will be no different.
The fuel either drains back to the tank, evaporates or seeps somewhere.
Unless you fit an electric fuel pump ( which I think is worth doing) you will have to crank the engine to get the mechanical fuel pump to fill the carbs.
Ahh the joys of classic motoring.

Clive

[miked]

Tony,

I to have an S4 Stromberg and it is the same. I am considering an electric pump and pressure regulator. The cranking is a bit annoying.
It must evaporate.

Mike

[archigator]

I have the same issue with my Webers, and they're not leaking. However, I'm a bit of a purist, so I'll stick with the mechanical fuel pump.

Gary
'71 Elan Sprint
Miami, FL

[thor]

And fit electronic ignition...... though it is slightly off topic, this might be a reason.
At least it'll alleviate the cranking effort needed, which is never too good for the life of the battery life and the starter.

[hatman]

Exactly the same experience with Dell 'Ortos. Give it full throttle while spinning it over on the starter for a few seconds as this reduces the effort seen by the starter motor, then take your foot off the pedal and revert to normal cold-starting technique.

[ianf]

I have not had the usual problems this year. It may just be that the weather is mild or that I haven't filled up with fuel in November and used less than a tank. I have instead filled up a bit a few times. Fuel fresher??

Ian

Ps the real answer is use the car more - they always go then.

[1964 S1]

Hello Tony, do you use your choke? Eric

[tonycharente]

Hello (again...) Eric,
Yes I do use my choke - there's no accelerator pump on Strombergs. I'll happily give it a try without the choke, but why did you ask this?
Thanks
Tony

[1964 S1]

I was curious, I too have the same symptoms with my Stromberg +2. I've never used the choke on that car as it doesn't help, even after extended non use. I crank the engine a bit if it's been sitting for weeks, then squirt starting fluid through a hole in the airbox while holding the throttle open. Get back in the car and vrrooomm, it fires up and idles fine without the choke. If I'm lucky enough to use the car daily it fires up almost instantly and drives away without choking.
My S1 with Webers will fire up quickly after sitting for weeks but only if I use the choke (no starter fluid needed). Both cars have orignal fuel pumps.
The +2's seem to have a fuel evaporate problem not shared with the two seat Elans.
Your idea of a one way shut off valve may be a solution but wouldn't it have to be near the tank and opened after the car has started?

[steveww]

Fit an electric fuel pump. My S4 has one fitted and if the car has been standing for a while it takes may be 10 secs after switch on for the carbs to fill up again. If you fit an electric fuel pump you must also fit a pressure regulator, a Filter King is the best option.

My S4 only needs the choke if the weather is cold. On a warm sunny day no choke is required and it starts first pull.

[thor]

If the mechanical fuel pump is the problem, isn't it easier to try first pumping on the primer pump under the fuel pump? Given that the access to the pump is better than under my Dell'Ortos, as I can't really get to it without the requisite Lotus 4-jointed arms and spiderlike 6-jointed fingers....

[miked]

Thor,

most of the newer pumps do not have a primer lever. Presume you must have an older type. Sound idea though!

Mike

[tonycharente]

Re the fitting of an electric fuel-pump: Clearly this would indeed solve the problem - it's what there is on my Excel and after a couple of weeks between starting it you get that nice reassuring ticking sound that stops after a few seconds. But I'd like to keep the car standard.....

Based on all the replies, it would seem that my "problem" is not a problem, but is perfectly normal. However it does seem to me that whilst the petrol in the carbs might evaporate, it might well also be that the petrol in the petrol pipe is draining back into the tank - I don't see how it could be evaporating from inside the pipe.... Hence my idea of stopping this with a one-way valve.

Your idea of a one way shut off valve may be a solution but wouldn't it have to be near the tank and opened after the car has started?

Yes, the one way valve would be mounted near the tank, but no need to open after the car has started - it would just allow flow in the one direction.

HAS ANYONE TRIED FITTING SUCH A VALVE, PLEASE?

[sparkey]

I think a bit of cranking to start the car after it's been sat for a while is a good thing as it gets a bit of oil around the engine before it fires. I'm going to stick with my mechanical pump and extended cranking !


Steve