Holly and Chris
I would suggest that if you are having trouble with rough idle that you
start with the ignition system verify that the points are good and set
right. Check and change the spark plugs if need be, gap them at the very
least. Check the distributor cap and wires replace if they are bad. If
this all checks out check and set the timing. Remember that the timing is
to the ball on the flywheel. If this looks okay move to the carb. Grab the
throttle linkage at the base of the carb and wiggle it. if there is a lot
of movement the throttle butterfly shaft and or the hole in the carb for it
have worn and you are sucking air that will affect the idle. Can you turn
the idle air screw in and stall the engine? If not you have air leaking in
some place. If all this checks out then lift the top off of the carb and
check the level of the float and the flatness of the top of the carb. Some
of the old carbs, such as the original on your truck, had a tendency to warp
and then allow fuel to leak from the float bowl in to the venturi causing an
over rich situation and bad idle. If all of this checks out take a butane
torch, like used for household plumbing repairs, and without lighting it
open the valve on it slightly so that their is gas coming out of the nozzle
then put torch tip down to the intake manifold where the manifold connects
to the head. Move along both the top and bottom of the intake manifold at
the head. If there is a leak the butane will enter the engine and the
engine will pick up speed or smoothen out. I have a 52 Chev with a 216 in
it and it idles so smooth that with the hood closed it is sometimes hard
hear running at idle.
Good luck and keep us posted with your results
Mac
52 Chev1300
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|