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Running Problem and I'm very Frustrated!!

19MGA60

Senior Member
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I am ready to drive my 1977 MGB over a cliff, but I live in Florida and we don't have cliffs. My car is backfiring thru the weber carb. So I had another weber and put it on and the same symptoms. It will only start if I pour gas in the carb and when it starts and I try to give it gas it backfires and also will pop fire in carb. I have changed distributers and set timing but the symptom continues. I have 160 compression in all 4 cylinders. I am thinking it could have jumped time. What does everyone think?

Thanks for your help.

Tom
 
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... I have changed distributers and set timing but the symptom continues. .....

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Hi Tom,
i would start here i think..pull the valve cover and double check the timing.

Did it ever run well at all?
have you checked that you have correctt fuel pressure?sounds like something in the float bowl..water?but you said you changed carbs.
Manifolds leaking air?


hmmm
love a mystery

mark
 
Tom, I know this sounds stupid, and please don't take offense, but are you sure the plug wires are in the correct order at the cap?
Stranger things have happened.
Jeff
 
[ QUOTE ]
I am ready to drive my 1977 MGB over a cliff, but I live in Florida and we don't have cliffs. My car is backfiring thru the weber carb. So I had another weber and put it on and the same symptoms. It will only start if I pour gas in the carb and when it starts and I try to give it gas it backfires and also will pop fire in carb. I have changed distributers and set timing but the symptom continues. I have 160 compression in all 4 cylinders. I am thinking it could have jumped time. What does everyone think?

Thanks for your help.

Tom

[/ QUOTE ]

Sounds to me like timing either distributor ( but you said you replaced the distributor) or cam out of time. The compression readings seem a little high to me also. Take the valve cover off, remove the plugs, and rotate the engine until it is coming up on the compression stroke verifying with the valve positions and see if the distributor is coming up on plug wire # one. If not, you probably jumped cam timing.
If you replace the timing chain, replace it with the double chain and sprockets used in the older engines.
Bob
 
[ QUOTE ]
It will only start if I pour gas in the carb and when it starts and I try to give it gas it backfires and also will pop fire in carb.
Tom

[/ QUOTE ]
If it only runs when you pour gas in the carb, it must not be getting gas. The poping is a symptom of very lean mixture.

Loosen the fuel supply connection closest to the carb, crank it over, & see if anything comes out. If not, check fuel supply to the carb. Pump, filters, lines, etc. If fuel comes out, check the carb fuel inlet needle & float for dirt or stuck. Not likely the carb inlet/float since you changed carbs, but still a possibility.
D
 
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