Yup! mines the same Mark.. I notice as the oil pressure drops off as it gets hot [quite a bit], and idle gets a bit grumpy.



"Came too close to dying to stop living now!"

There is no doubt in my mind that air temperature has  a lot to do with the way these old Fords idle.For most of this summer which has been extremely warm mine doesn't idle very smoothly in drive.Adjusting idle mixture has no real affect.The last 2-3 weeks which have been much cooler mine runs like a watch.Overall runs much better in the cooler weather.I am thinking gas quality has something to do with this also.

  

AS above, also check your float levels too and a 1/2" phenolic spacer may help [if you can fit it]



"Came too close to dying to stop living now!"

Adjusting the carb. idle mixture is done after distributor point dwell angle, and initial engine timing have both been adjusted or checked for correctness. Initial engine timing is adjusted and set with the vacuum advance line between the carb. and the distributor disconnected and taped-off. It is critical to set the initial timing with the engine at the proper engine idle rpm.



I adjust the idle mixture screws on a carburetor with the engine at normal operating temperature using a tachometer or a vacuum gauge. I prefer the tachometer, it seems more telling of screw adjustment.



In addition to the engine being at normal operating temperature, the engine idle speed must be correct before beginning idle mixture adjustment. Check engine idle speed with a tachometer. For an auto. transmission car, block the wheels, put on the emergency brake, and put the car in gear to attain proper idle speed. Alternative method... leave the car in Park, reduce the idle rpm using the throttle adjusting screw on the carb. Don't forget to readjust this when you are done.



If using a tach., adjust one idle mixture screw at a time adjusting for maximum r.p.m. reading. Turn the idle mixture screw approx. an 1/8 turn at a time and watch the rpm reading. Take some time doing this, it takes a little time for adjustments to be accurately reflected in the tach. reading. Go back-and-forth between the two adjusting screws to insure that adjusting one hasn't affected the other.



If using a vacuum gauge, again adjust one idle mixture screw at a time adjusting for maximum vacuum reading. Turn the idle mixture screw approx. an 1/8 turn at a time and watch the vacuum reading. Take some time doing this, it takes a little time for adjustments to be accurately reflected in the vacuum guage reading. Go back-and-forth between the two adjusting screws to insure that adjusting one hasn't affected the other.



Remember to check and adjust the engine idle rpm as called for as you do the above. Adjusting the idle mixture screws (especially if they are presently out of adjustment) will significantly affect engine idle speed.



When done, remember to reconnect the vacuum line between the carb. and the distributor.



I'd do the above work before looking for a cause for the stumble you reported. It may 'go away' after doing the above.



Hope this helps!










NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

I can't help with your specific carb problem, but the right side of the carb does not feed the right bank and the left side feed the left bank.  The manifold ports are arranged so that one side of the carb feeds #s 1,4,6, and 7, the other side feeds #s 2,3,5, and 8.

John - "The Hoosier Hurricane"

Hi guys. I know this has been covered a million times. I have a 57 tbird with a 312 - Fordomatic. Holley 4 barrel 4160 model - 465 cfm. Vacuum reading is 19 inches. The idle mixture screws are turned out 1 1/2 turns per side. When I first start and drive the car and its running cool the idle is very smooth. Acceleration from a stop is good. As the engine gets hotter the car develops a idles rough. I had read in a past post to lean out the mixture. I did that and it worked. The idle is again perfectly smooth when the car is at full operating temperature. However when pulling away from a stop, the car stumbles. Another issue i had was a lumpy idle where the engine would rock from side to side. The mixture screws were turned out 1 1/2 turns per side. When I leaned out the right side by 1/2 turn the rocking was eliminated. I am thinking perhaps the right bank does not require as much fuel as the left side. Is this possible?



Thanks all.