Fuel Flowing out Carb when running

[Temmck]

The S4 was running a little rough the other day. When I pulled the car into the garage and opened the hood (with engine running) I saw fuel flowing out of the front Stromberg carburetor. These are recently rebuilt carbs with kits from RD. Assuming one of the common causes of sticking float valve or floats taking on fuel, I disassembled the carburetor. I did not find either condition but I did notice that the new floats have a ridge around the belt line. This ridge was getting hung up on the new gasket which protrudes slightly into the float bowl, not a lot but enough to catch the lip of the float and keep the float valve open. Trimming the gasket facing the sides and front of the floats resolved the problem.

[elanfan1]

Good spot before the car burnt out!

Hope you have some decent sized extinguishers to hand.

[Temmck]

I am very sensitive to any changes in behavior since the car is still in shake down mode for being off the road for over 30 years. I am currently running it without the air box and open the hood and check under the car after ever drive to inspect for anything unusual. But I am considering adding a deflector shield (not the Star Trek type) under the carbs so than any leaking doesn't drip on the coil.

[USA64]

Nice work! My car came off the road in 87 for just that issue. It's still off. I will check that for sure!

[elanfan1]

I am very sensitive to any changes in behavior since the car is still in shake down mode for being off the road for over 30 years. I am currently running it without the air box and open the hood and check under the car after ever drive to inspect for anything unusual. But I am considering adding a deflector shield (not the Star Trek type) under the carbs so than any leaking doesn't drip on the coil.

Unsure if that would have much benefit as it would be the vapour that would ignite.

[The Veg]

The Star Trek type would be a most excellent idea though to protect against morons piloting larger vehicles.

[LotusElon]

Good catch - another cause would have been a dodgy float valve, or leaking submerged float. ( yep been there and don’t miss it )

[Andy8421]

But I am considering adding a deflector shield (not the Star Trek type) under the carbs so than any leaking doesn't drip on the coil.

If the connections are tight on the coil, there should be no sparks, and no source of ignition. The distributor however is a different story entirely. A distributor can easily ignite fuel vapour, and a carb dripping fuel onto the distributor is likely to lead to fuel vapour building up inside the cap. This should be avoided at all costs.

[smo17003]

This looks like an interesting product to keep an eye on potential fuel leaks. Not only at the engine but also the fuel tank. Has anyone previously used UV detection systems on their cars?

https://www.ringautomotive.com/en/product/RLD4

[Bits]

I'm in a similar situation as I'm completing a total resto of a S4 elan with refurbed Stromberg's.
I have fitted a electric fuel pump and pressure regulator.
I suspect my front carb is not shutting off when the float bowl is full.
I need to remove the carb and check it out.

[jono]

This is one of the reasons I went distributorless on my last Plus 2

[Bits]

Distributorless?

Do you mean replacing the contact points with electronic ignition?

Regards,

Mark.

[69S4]

I'm in a similar situation as I'm completing a total resto of a S4 elan with refurbed Stromberg's.
I have fitted a electric fuel pump and pressure regulator.
I suspect my front carb is not shutting off when the float bowl is full.
I need to remove the carb and check it out.

You might want to add the float bowl O ring - the one sealing at the bottom - to the list of things to check. The one on the front carb started leaking copiously all of a sudden back in the summer. When I had a look it was perished to the point where it snapped taking it off. A new one stopped the leak.

[englishmaninwales]

Distributorless?

Do you mean replacing the contact points with electronic ignition?

Regards,

Mark.

I presume he means the distributor deleted altogether, with plug top ignition coils with wasted spark ignition run by a programmable ECU, flywheel trigger and cam phase sensor (if the latter is available with modern replacement TC camshafts?).
Malcolm