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1965 425" feels like misfiring

1965 425" feels like misfiring

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Old October 11th, 2018, 12:28 PM
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GCH
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1965 425" feels like misfiring

Hi my Olds Dynamic with 425 ultra high compression and 2 jet carb are a little strange.
Should try to explain , runs fine on idle and highway driving at low rpm but if i came to a crossing
and need a little more power the engine feels like misfiring and feels like poor power,can feel vibrations of
this in steering wheel and car.

Runs fine when i rev it up in Park , the issues came under load.

ignition set and dwell ok ,new coil,points,condesator,rotor,cap,wires,plugs,vacum advance clock,timing gears.

The carb is a rebuilt carb from Autoline and vacum advance taken from the carb.

Regards Glenn in Sweden
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Old October 11th, 2018, 02:13 PM
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Verify that that you have good fuel delivery to the carb. Take the fuel line off of the carb put it in a container and check how much fuel comes out while cranking (you should probably disable the ignition). You want to see about 375 ml in 15 to 20 seconds. If you arenít getting that, check for restrictions or leaks between the fuel tank and fuel pump, plugged sock in tank kinked line, plugged line, maybe a leaking check valve in fuel pump, a leak in this area will allow the pump to suck air.

Happy hunting,

Gary
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Old October 11th, 2018, 09:58 PM
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GCH
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Thanks for tips, should check for air leaks. Fuel pump and fuel filter are new but maybe the car can, t get enough fuel.
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Old October 13th, 2018, 01:29 PM
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Tough call, many gremlins can cause this problem. Maybe new battery cables, clean grounds are very important. Is the fuel an ethanol blend 10-15% ethanol like in the US: A lean condition under load would signal a lean condition, but there are many factors as gs72 mentioned, some as obscure as a plugged exhaust.
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Old October 13th, 2018, 03:11 PM
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Most "carb" problems are really ignition. When was the last time you tuned it up? Replaced the plug wires or coil? How old is the timing chain?
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Old October 13th, 2018, 04:08 PM
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ignition set and dwell ok ,new coil,points,condesator,rotor,cap,wires,plugs,vacum advance clock,timing gears.

this is when
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Old October 14th, 2018, 12:18 AM
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GCH
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Hi,was under the car and checked the fuel tank and the fuel feed hose was almost flat under
the "support tab" on the body. The car feels better now but i should replace the hose as soon as
the fuel level in tank are lower and testdrive more. The hose feel very "soft"
Could see in my 1965 Olds Chassies manual that there should be an "saran" filter on the suction end
in the tank so that maybe be next step to check ( if i find where to buy this filter )
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