Topic: 65 FB Diagnostic

[ChrisV289]

Was hoping maybe someone would have some insight.  My Mustang seems to be hesitating and doing a slight jerking motion after it hits 45 mph and anything above that.  Any speed below that is fine....I've changed the fuel filter and sprayed the heck out of the carb with some carb cleaner....Do you think the carb needs to be rebuilt or could it be the spark plugs, or something entirely different...

Thanks

[CharlesTurner]

Could be any number of things.  Is the engine recently rebuilt and/or a new camshaft?

[mgmradio]

  Sounds like you have a miss.I would look at the plugs , wires and cap/rotor.And don't forget the points and condenser.

[ChrisV289]

Engine was rebuilt back in 2003-2004.  It does have the original Autolite 4100 that was also rebuilt.  The jerking motion is not drastic but I can feel it.  It doesn't have points anymore...That was changed awhile ago...

[CharlesTurner]

You might try putting the points back in as a test to rule out ignition.  Guessing you're running a petronix?  How about the coil?