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Discussion Starter · #1 ·
I have a 62 cloud that was running fine until I filled up...and it started backfiring like crazy and no power...it idles fine ...I replaced all the gas...plugs... wires and distributer cap...it is still backfiring...I also was told it could be the fuel pump...i replaced that too....anyone have any ideas?
 

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I'm with @Wraithman. Water in fuel should not cause backfiring.
 

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Odd why it would start back-firing just after a fuel fill up _ probably just coincidence ?
If the spark timing checks out, check that both the carburetor pistons move freely up and down.
Make sure the oil is topped up in the damper tubes.
Check that the automatic choke is fully off when the engine is fully warmed up.
Make sure the float valves are not sticking on and that the floats themselves are not leaking and filling up with fuel.

The fact that it idles fine would indicate that there is no water in the fuel, if there was, it would not idle at all.

Another thought, if too much fuel was added, it's possible that some got into the breather system of the fuel tank.
I don't know how that system is designed in a Cloud 2, if it's simply vented out into the atmosphere, of vented into the intake manifold of the carbs, but I think it would require some investigation.

And to the OP, is it back-firing from unburned fuel in the exhaust, or popping back from a too lean condition ?
 

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Odd why it would start back-firing just after a fuel fill up _ probably just coincidence ?
Backfire / misfire / running like crap are often interchangeable terms. He said it idles fine so the problem happens under load, and it all started when he filled up. If that's all that happened before the issue, that's where I would look first.

As the OP said that he drained the fuel. it makes sense to look elsewhere. My guess would be the ignition system (points, rotor, coil etc.) and not fuel unless it's something like stuck floats.

I don't know anything about carbs so I'll stay off that topic.
 

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I should have added, all ignition possibilities should be ruled out before assuming carburetor problems.
Although checking for sticking dash pot pistons and damper oil is very simple and easy to do.
 

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Discussion Starter · #9 ·
Odd why it would start back-firing just after a fuel fill up _ probably just coincidence ?
If the spark timing checks out, check that both the carburetor pistons move freely up and down.
Make sure the oil is topped up in the damper tubes.
Check that the automatic choke is fully off when the engine is fully warmed up.
Make sure the float valves are not sticking on and that the floats themselves are not leaking and filling up with fuel.

The fact that it idles fine would indicate that there is no water in the fuel, if there was, it would not idle at all.

Another thought, if too much fuel was added, it's possible that some got into the breather system of the fuel tank.
I don't know how that system is designed in a Cloud 2, if it's simply vented out into the atmosphere, of vented into the intake manifold of the carbs, but I think it would require some investigation.

And to the OP, is it back-firing from unburned fuel in the exhaust, or popping back from a too lean condition ?
I think the fuel fill up was an odd happening...i was checking the floats and the back fire seemed to occure right in the driver side float dome...the roter was replaced with the cap...i am having the points and timing checked... trouble is i dont have a good machanic in the tampa bay fl area...most will mot even look at the car
 

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The only time I've had backfiring on any car was in SRH33576 when the Lucas Opus ignition was on its way out and would begin misbehaving when hot. It seemed to be a combination of misfiring (lack thereof) on certain cylinders once the ignition began acting wonky once hot and then sending the unburned fuel down the exhaust system into a very hot muffler somewhere (that car has no cats) and it exploding there. That's my reason for suspecting an ignition issue based upon the data that has so far been offered.

And I agree with @Jeff R 1 that ignition issues should be ruled out before starting to dig into the carbs other than making sure the dashpots have lubrication.

I cannot imagine anything I'd call a backfire occurring "right in the float dome." So this now makes me wonder what, precisely, is being heard when whatever's happening is happening. Audio/video from a smartphone is worth a million words in situations like this.
 

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I would be looking at a failed ignition condensor or coil and coincidence that it happened after filling with fuel. Classic sign of a failing coil or condensor is idling fine but backfiring and missing heavily upon load, like revving the engine. You state you have already replaced spark plugs, were they black and sooty or tan color? If you put a new rotor in was it aftermarket or Lucas old stock? Have you checked point gap?
 

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Do what Jim said first, changing to electronic ignition won't help unless you replace the coil and the condenser too, so you may as well start with that.
Changing to electronic ignition only replaces the points, you can still have failure with it if the coil is faulty.
If you start by changing too many things out at once, you'll never find out what's wrong.

I've had these aftermarket electronic ignition fail on me at least three times, 2 with the Bentley and one with a TR7 many years ago.
2 with Pertronic's and one with Lumintion.

If I had to go with one, I would go with 123 Ignition, that one even eliminates the mechanical advance weights, but it's not inexpensive.
 

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123 Ignition, that one even eliminates the mechanical advance weights, but it's not inexpensive.
I've heard lots of good things about 123 ignition. They have a distributor that replaces the Bosch D-Jetronic trigger points used to fire the injectors on the early EFI Mercedes Benz. If anyone has ever dealt with that system , it can be a huge pain.
 

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Often techs want to be heroes and blame the car and it's engineering and they make changes and you end up with a large repair bill and poor results. Points in these cars have lasted for decades.
 

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Points in these cars have lasted for decades.
I won't argue that, because it's true. So have the electronic ignitions once Crewe began using those.

I see nothing wrong with choosing the ignition type that makes you, the owner, most comfortable. You can always keep whichever is being removed in case someone else (or even you) would ever want to go back to it.
 
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