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Fuel thru Carbs [or not]

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BruceAllcorn

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I'll try to keep this short - went for a drive, got back home, turned the ignition key off, car kinda backfired and then shut off as it should. Tried to restart, but to no avail. The engine turned over but didn't even attempt to fire. This much I know - timing is OK, have proper spark at the plugs and have fuel at the carbs. Rather than pulling off the air cleaners, I pulled the vacuum line off the rear carb, sprayed a little brake fluid, hit the ignition switch and the car fired (probably on just 3 cylinders). Therefore, I'd bet that something to do with the carbs has happened and they are not taking in and distributing the gas as they should. The spray was used on the rear carb only, but the front carb must not be getting (enough?) fuel either. So the question is - stopped up fuel line starting at the first carb? - not enough pressure from the pump? - any ideas/suggestion would be appreciated.

Thanks,

Bruce
 
Ticking at pump? Pull fuel feed-line to carbs and see if you are getting delivery. Backfire is common when carbs are lean so poor fuel delivery may cause lean mixture. Do you use a fuel filter? It could be clogged even if it looks clean (if clear plastic filter).
TH
(I would not mess with the carb adjustments until you have checked everything else first. They don't get out of adjustment by themselves.)
 
I don't know what the temperature is like in North Carolina right now, but these cars get hot under the hood really quickly once you turn off the engine. Boiling fuel in the carburetor bowls will cause the problem you describe (i.e., the car runs fine until you turn it off and then try to start it again). Next time it happens, open the hood and blow some air on the carburetors and see if that helps.
 
Bruce

Are you running HS6 carbs ? There can be an issue with the feeds from the float chamber to the jet. What colour are your spark plugs?

:cheers:

Bob
 
Thanks for the ideas, but I just found the problem. I presumed that since the engine didn't seem to be getting fuel the problem was in the carb float/needle and seat setup. I wanted to check the actual floats while the bowls were open, but to get the float on the rear carb out of the bowl I had to take off the choke cable bracket that was under one of the nuts that holds the air cleaner on. In taking that nut off I dropped it, and when I leaned down to reach under the car to retrieve the nut I found a round piece of metal approximately 1-1/4" in diameter and shaped like a saucer. I went ahead and finished my "rebuild" of the floats on each carb, hooked everything back up and attempted to start the car and -----same old same old! Fully choked it would spit and sputter but that's all. It was then I thought I might want to find out where my little piece of round metal went. In the end of the intake manifold there is a hold in which the piece of metal I found presses in, kinda like a freeze plug. And when that piece blows out, the engine isn't going to run. I pushed the plug partially in, put some tape on it so that if it blew out I wouldn't loose it where I couldn't find it, and started the engine and she purrs like a kitten. If this had happened on the road somewhere instead of in my garage - well, I guess in this case I was very lucky. Two questions - Has anyone ever heard of this happening? If so, any ideas as to how to reinstall the plug so that it will stay in? I was thinking maybe a little spot of J & B Weld at about four places around the outside of the plug.
 
Happened to me on the road but, fortunately, not too far from home. Required a trip on a flatbed hauler courtesy AAA.

I put the plug back in. The trick, with the engine in the car, is to get enough force on the plug to seat it adequately. Forgot exactly how I did it, but in afterthought realized using a 1/2" breaker bar as a hammer probably would have worked; you don't have to pound it hard but you do want it to seat all the way in (IIRC, there's something to stop it going too far). Whatever I used, I ended up gouging the firewall heat shield which is bad because a) it's original and I screwed it up and b) it's original hence it's asbestos and you don't want to disturb that stuff. I applied JB Weld around the periphery of the plug--it's held for many years and miles (and more than a few carburettor backfires, which is what probably caused the problem in the first place).
 
I ended up wire brushing it, cleaning it with brake cleaner and then I put it in the hole as "square" as I could see and tapped it with the male end of a 3/8" drive ratchet handle. It seated fine and it now has J & B applied and drying. Thanks again to all!
 
I don't know if they are made in the size needed but Dorman makes brass plugs that expand by tightening a nut. I use them, seated in JB Weld, to replace the freeze plugs on my race engines.
 
Yet another series of testimonials to JB Weld. I'm sure many members saw Wayne Carini's patching of a hole in a Cobra fuel tank with JB. I thought that was a bit over the top, as was his crawling under the car without a jackstand or other secondary support.
 
When I was 16, (1962) my brother found a TF1500 sitting in a gas station in Philadelphia. It did not run and had a very faded paint job. My dad paid the $500 for it and we towed it home. My brother was a good mechanic. We opened the hood (bonnet) and were looking at the engine to see what was wrong with it. I noticed a hole in the front end of the intake manifold and asked my brother if it should be like that. He said no and found a cork in the garage workshop. He tapped it in place, turned the key, pressed the starter and it fired right up. Then we got some rubbing compound and brought the paint to a shiny red state. We had a perfectly running and looking vehicle that only needed those two things to get there. That was the beginning of my lifelong connection with LBC's.
 
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