I’m pretty sure I’m not ready for this education yet…

Geez, one think after the next……

I got my volt meter out to try to start learning about why my hazard warning lights aren’t working. I dropped the gauge panel, moved the key to the on position, and was poking around to learn about various voltages.

It took me a few minutes to realize the the fuel pump was still clicking every 5-10 seconds. Normally it clicks a few times and stops. So I turned off the power, got out of the car, and immediately smelled gas and found a small puddle under my air filter canister.

Took the air filter out and several more tablespoons of gas poured out.

I have a normal ‘68 dual Zenith Stromberg setup:

When I looked into the air intake opening, the rear was dry, but the front had a puddle of gas in there. It’s still a bit wet in this pic:

No leaks in any of the lines going into the carbs.

So, how bad is this likely to be?

The carbs terrify me… :slightly_frowning_face:

It is most likely that either (a) the needle valve in that carb is stuck open, or (b) the float in that carb has sunk due to it filling with fuel from a pinhole leak. Either way you are probably going to have to remove the float chamber from the carb to diagnose be and fix the problem. A search of the archives should yield advice on the way to do this. Good luck!

1 Like

Carbs are actually very simple…just study up on them

If it is only a stuck open needle valve, what is the usual fix: cleaning (ultrasonic?) the needle/valve or else?

If its a stuck needle valve, a slight “tap” on the float bottle may free it up. JS

I had twice recently gas flooding from one carb to the floor when starting the engine, actually already when the fuel pump was running before ignition.
That happened after having left the car non running for a few weeks.
Fortunately indeed “tapping” on the float bottle freed it up.

I understand that this standing period may lead to such open stuck needle valve.
But is it due to gunk from drying gas, surface rust from water in the gas or else?
Because the cure in the long term (except driving more frequently :wink: ) may not be the same…

When I brought my car home for the first time I found fuel dribbling out of that small hole at the 10 o’clock position on the rear carb. I knew nothing about these carbs and was nervous but figured the worst that would happen is I would have to send them to a guy like Joe Curto anyway so I dived in. I bought a couple of rebuild kits. I then removed both carbs as a set by un-doing the 8 nuts that hold them both to the manifold but I did not disturb the shaft or any of the clamps that tie them together. On the bench I took off the bottoms and tops, blew them out with carb cleaner and replaced many of the gaskets and seals etc from the kits. As others have said I was pleasantly surprised how uncomplicated they are compared to the Rochester and Holley carbs I had played with before. I found the hollow float on the rear carb had fuel in it and had sunk and the culprit for the fuel overflow out of the small hole. Later on I found you can remove the float bowls with the carbs still in place on the car. If your carbs are unmodified from 1968 then pretty much the only adjustment you can make is to the float level as explained in the manual.

68 E-type FHC


What a disappointment. I was really hoping to login and see, “Ohh, that’s really complicated stuff Ed, don’t try to learn about carbs, you’ll just mess them up, pay an expert”. So then I could go to my wife and say, “See, I can’t do this myself, I need to pay somebody else for this”.

Instead, all I’m hearing is, “suck it up, roll up your sleeves, and learn about your car! It’s not that difficult! You can do this”.


To be honest, when I was thinking about installing my CoolCat fans, or thinking about taking off the filter head to figure out my oil pressure problem, I was SURE that I wasn’t ready to learn about either of those. And yet, with a bunch of help from all of you (and a few sessions with my personal psychologist, Dr. Wiggles), I jumped in, read the manuals, and eventually figured it out.

These ‘pep talks’ are immensely helpful, thanks for the patient encouragement!!

I am not sure yet that I need to buy full rebuild kits, and take the carbs out of the car, but I’m gonna learn what a needle valve is, the float, float bottle, float chamber, etc. As @D_Barnes properly points out, even if the worst happens, it’s recoverable.

I will update this thread with my obligatory (and possibly getting old), “thanks everybody, you were right again, I figured it out, and am back on the road again!”.


I’ve done the tapping on the float bowl trick and it has worked. Another thing you can try is revving the engine a little maybe 2k rpm, pull on the choke briefly the rush of fuel may flush out any loose obstacle around the valve seat.

Oh, Eddy…I am now very worried for your well-being.


My car had the same problem you are experiencing. Drove me crazy. I bought a pair of floats from Joe Curto and haven’t had a problem since. And for what it’s worth your carbs, the Strombergs, are pretty simple things to work on.

I bought a couple of these kits from Rock Auto. Take your time and follow the directions and you’ll do fine.



Is Float Chamber, the same as Float Bowl, the same as Float Bottle? This lowest part of the carb?

Is it OK to start the engine with the air filter canister and plenum out, for a few minutes, just to see if gas is leaking still?

Yes, yes, and 30 more floaty yeses!

Just turn on the key: if float valve is stuck/float is sunk, gas will pour out.

I used the round end of a 3/4” socket wrench, and tapped/gently banged on the float chamber 8-10 times, turned the key on, and nothing happened. I left it on for 5 minutes, still nothing. Last night, there was a full puddle in there after just a few mins, and many tablespoons of gas on the garage floor.

I pulled the choke out, and she fired right up.

I don’t love this, but now I know more. Is it likely that this will happen increasingly more? Or have people seen it happen just once, and then not again for a long time?

At a minimum, Id replace the inlet needles: check the floats when out if they’re sunk.

Also be prepared that those four parts will exceed $150…:confounded:

My first thought about your predicament is that it reminds me of my first venture in car ownership 45 years ago. I had a '65 Triumph TR4 that had dual ZS carbs. I was forever dissatisfied with the unpredictable idle, and quickly learned that I didn’t have unlimited money to take it to a garage for ‘adjustments’. I learned quite quickly to either suck it up and do my own work, or sell the car. If your current car problem is going to keep you from driving it, you are not going to ‘break’ it by attempting to ‘fix’ it…“It is already too broken to break it” is my philosophy when it comes to problems like what you have. You need to do some reading, ask questions as you proceed and fix this current hiccup. I would contact Joe Curto and get the rebuild kits and end your current misery. I would not be able to confidently drive my car if I was worried that I would come out to the car in some distant destination and find a puddle of gas under it.

1 Like

Since you may be at that point I’ll mention one change I made to make future service easier when removing the bowls with the carbs still installed.

I replaced the screws holding the float bowls with socket head cap screws. I find that those are much easier to undo and do compared to the original slotted screws.

The screws on the front carb are the trickiest to get to.


The likely issue is, as others have mentioned, either the Needle and Seat unit, or the Floats are holed. In either case, you won’t have to start the engine, in fact, you will get a quicker result if just the ignition is on, thus running the fuel pump, and the engine not running. There are breather holes for the float chamber at circa 10 and 2 o’clock, relative to the intake throat, on the face of the intake flange (the face the air filter box attaches to). If the Needle and Seat isn’t stopping the flow of fuel, through either being faulty, or not being shut off by the the floats, then the float chamber fills up and eventually overflows through the breather holes in the face of the intake flange.

With an S3 car, its just about impossible to remove the float bowl with the Carburetors in situ. You might do it with and earlier car, but ultimately, if the floats have to be replaced, the carburetor has to be inverted to set the float height. Accordingly, I would cut to the chase and remove the carburetors if its determined by fuel flowing from the breather holes, that the Needle and Seats are not shutting off.


1 Like

It has not happened lately but I have had a few cases over the years where after sitting for a couple of weeks a float needle will stick and tapping the carb around the float bowl will free it and make things nice again. My car is pretty good about a nice smooth idle and good throttle response when starting off from a stop so if it starts missing at a stop light or has poor acceleration the first thing I will do is pull the air filter plenum and check those overflow holes. This is how I found out I had a sunk float again a couple of years after my first carb “rebuild”.

68 E-type FHC

R&Ring carbs and setting up floats is not especially hard. I can’t even recall how many times mine have been off and back on again. But, you must take your time, and double check your work. Home mechanics tinkering with their carbs is probably the number one reason these things go up in flames, and plenty of them have done exactly that.

Hopefully you have a factory manual. Read through the relevant sections several times and ask for clarification where necessary before beginning. I suspect worn needles or debris in the chamber from a failed fuel filter. A sunk float can certainly cause it but I would expect that to flood instantly and persistently, whereas needle problems can be intermittent and they definitely do wear and get contaminated.

1 Like