Back firing problem

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hawkgoalie31

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I have a 74 duster 318 with a edelbrock carb and intake. Whenever I drive up this steep hill by my house near the top it back fires really bad. Its only this one hill that it does it. It never does it on any other hill and when I get on it. Althouth this hill is steep this problem worries me. My dad and I have replaced the fuel filter the fuel pump and sending unit are new and the timing is right on.

Any suggestions please,

Thanks,

Brian
 
Make sure the vacuum advance is not hanging up and keeping your timing too advanced. Next, take a look at the plugs. If you are running rich they should show it.
 
CUDA69 said:
Make sure the vacuum advance is not hanging up and keeping your timing too advanced. Next, take a look at the plugs. If you are running rich they should show it.
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What do you mean by the vacuum advance hanging up the timing?
 
What is your definition of "backfire?" That is, noise/ etc out the exhaust, or is it spitting back through the carb? If it's spitting back through the carb, is it a real "rythmic" miss?

ANY real hard load will show the weakness of stuff like

(Points ignition) points or condenser going bad

Coil that is weak

Weak plug wires

Plugs

Can also be:

badly worn lobe on the cam

If it's a fairly "intermittent" and unpredictable lurch or spit, might be poor fuel delivery---pump going bad, plugged filter or suction line, etc.
 
I bet I know what it is (this is only if it's backfiring thru the carb)....I would say the carb is probably hitting a "lean spot" when he hits that hill and gets under load and the metering rods aren't reacting quick enough....maybe the springs under them are too weak or just jetted a little lean? I've heard many times that backfiring thru the carb is a lean condition.

If backfiring thru the exhaust pipe, my guess would be that gas is flooding down the carb from the float bowl, from the extreme angle of the hill.
 
cudavert said:
........................the carb is probably hitting a "lean spot" when he hits that hill................
Click to expand...


I'm not sure it would cause that, maybe------could be something plugged int he carb and the power metering circuit is "barely working"
 
Thanks for the responses ill clear some things up. It is 100 percent out of the carb and its llike a loud wisk sounds. Everything on the car is new. New carb, new fuel filter, fuel pump, sending unit, plugs and wires, the only thing that is orginal is coil. So in the case anyother suggestions.
 
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