Cold start problems

Cold start problems

Mrhollywood,

Ok so my car starts up fine with two pumps of the gas pedal

One shouldn’t need to pump if choke is functioning properly. One full depression of accelerator to floor should set choke, and high idle. Pumping will flood engine, and sometimes unsets choke and high idle.

bu

t it runs rough with the choke closed, like its misfiring...the car shakes like crazy until its warm

This can be caused by that second pump wetting one or two of the spark plugs with raw gas… My bet would be #6 is getting baptized perhaps #5 as well, so engine is running on 4 or 5 cylinders. Once plug dries from engine pumping air through cylinder, the charge will light off, and engine will smooth out.

You need to correct this partial flooding problem, all that raw fuel is washing oil film off of cylinder walls causing excessive wear, and thinning oil in sump which will take out bearings after a while.

I think my choke spring isn't working all the time

Check for rod linkage pivot points for binding from excessive wear, dress these spots with a small fine file until any ridges are blended, and parts move freely.

I'll try richening the fuel mixture

Warm up engine first, than adjust idle mixture screw for highest idle speed and vacuum reading. Don’t just give’em a turn.
Colds start mixture is controlled by amount of pull off after light-off. You can move choke plate by hand as engine warms to fine tune pull off setting if you don’t have a dimension form manual.

One possibility is this carburetor is need of a good cleaning, and freshening up with a rebuild.