I am getting a little hesitation or stumble off idle (when I am in gear, under load, but not when I rev the motor in park or neutral). I have a rebuilt 292, 12 volt system, 55 Fordomatic, no binding in the linkage, rebuilt carb (the carb is a small 55 2 barrel - original), and a 57 and up distributor with ACCEL pointless ignition.

The car starts and idles fine, and revs fine while not in gear. But I have to feather the gas when she is in gear, because off the line she hesitates a little bit. Could this be the power valve in the carb? I did replace it when I rebuilt the carb just 2 months ago.

Hoosier Hurricane - I took out the 55 for her maiden voyage last night, and you were right on about the "overheating" problem...she settled down just fine when we were moving, right around 190.

Dan

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

g'day dan

you could check the power valve it could be stuck i would also check your accelerator pump as i have seen these cause a flat spot under load but fine on no load its possible being a new engine & being a little tight the pump needs adjusting to discharge a little more fuel i had this problem when my 272 was new i adjusted my accel pump to deliver abit more fuel then after i run it in i was able to back it of again.

moz.

moz. geelong victoria australia.

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The '57 and up distributors and carbs are technically not compatible with '56 and earlier distributor/carb combos.  Prior to '57, Ford used the Load-O-Matic distributor which required a specific carb tailored to the application being used.  No mechanical advance was supplied in the Load-O-Matic distributors.  For the Load-O-Matic distributor to work correctly, the carburetor used a vacuum port above the throttle blades, a vacuum port just under the venturi, and a spark valve to send the proper vacuum signal from the the carb to the distributor.  When installing a '57 and up distributor in conjunction with an earlier carburetor and hooking up the vacuum signal to the original location in the early carb, there is ultimately too much ignition advance due to too much vacuum signal being supplied to the distributor as the rpms increase.

The early carbs when being used with the later distributors can be modified so that only the vacuum from the port just above the throttle blades is utilized.  This involves either drilling a brand new vacuum port or hole in the carb or modifying the existing circuit so that the hole under the venturi is effectively blocked off and disabling the spark valve.

With all that said, there could still be an issue with the carb itself or the distributor.  Using a timing light, insure that the initial timing is set correctly and smoothly advances when the engine rpms are increased.  As previous posters suggested, double check the carb in the area of accelerator pump linkages and the power valve.

Lorena, Texas (South of Waco)

It seems to do much, much better after the engine has warmed up to about 190 or so. The linkage seems to be operating ok, and I know the timing is right on, with maybe a touch (a degree or two) more of initial advance.

I thought power valve, because it only has a slight problem when under load. Ted, about the carb to distributor situation, I had always assumed that the 57 and up could be used with the 5 or 6 carbs with no troubles. I do know I had a 56 2 barrel on a 56 F100, but that was with a standard transmission. I cannot remember any hesitation problems with that one, and I had rebuilt that carb after putting in a fresh 272. Maybe someone had already modified that carb and I could not tell. I did notice upon first fire up of my 55 a little while ago that the advance did seem to come in quick...

Maybe I am just a little "nitpicky". My original plan is to break in the motor (now to seat the rings) for the first 500 miles or so with the original setup that I am used to, and then make some modifications. I have a small 4 barrel manifold, a large 4 barrel manifold, a 3 deuce intake, etc. Would like to keep the Fordo for a few years, since it has only about 20K since a rebuild, and it is strong (I am squealing radial tires from a stand still with this 292!:w00t and the shifts are really positive. Any recommendations for the future concerning driveability for a street car?

Thanks, Dan

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com