Packard Forum Index » V-8 (1955-56)

Recent "improvements": rebuilt starter, carb (with new floats even-brass at that!), plugs, points, rotor, cap, fuel pump

The slight miss seems gone and the car runs very well when warmed up.

However, when I get it out of the garage and attempt to put it in drive, it stalls over and over. Push the gas a little, slowly and it stalls, Push it hard and it stalls faster. Hot or cold it starts right up.

What should I be looking at?

Stuck DD clutch?

No reason to believe that that I am aware of.....

I'm thinking the choke needs to be reconfigured a bit.....

Pat, this will not solve your current problems, but a refinement to a V-8 engine tune-up is to separate the spark plug wires for cylinders 5 and 7. They are on the same bank and fire consecutively which leads to some induction firing which causes a rough running engine. Place the wires for these cylinders at the far end of the brackets. Photo shows wire arrangement on my 55 Clipper.

(o[]o)

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It merely seems that your choke needs to wound up a notch or two tighter. The black plastic disc on the side of the carb needs to be turned slightly in the direction of closing the choke. You will see that it is marked with a series of notches. I'd try moving it one notch tighter. I'm several thousand miles from a Packard just the moment, but believe it would be ccw.

Things are getting worse.

Went to go on the Brighton run yesterday--after the choke had been reset a notch back--and the car flatly would not start in 40 degree weather in the garage.

The guy I was to pick up generously came over and pulled the air cleaner and held the choke shut while working the accelerator pump vigorously. Then I turned the key and it started, running rough. Backed it out of the garage and let it warm up for five minutes at which point we drove off and it ran pretty much as it should.

Before I had the tuneup and carb rebuild the car always started easily in this kind of weather.

What do I do next?

This is frustrating beyond belief.....

Uh, Pat, I said to do it tighter, not looser.

My language not withstanding, I believe it was moved a notch in the right direction.

Took it from starts but won't run when cold to won't start.....

Two forward and what? six back?

Well, lets go back to first principles: When the engine is cold, before you start it, if you open the throttle slightly the choke plate should snap lightly and completely shut. Opening the throttle allows the fast idle cam to set as the choke snaps shut.

If all goes according to plan, the mixture will be enriched enough to start a cold engine, and the flow of air will pull the choke plate open slightly. As the engine warms, hot air is drawn over a thermostatic coil that is located behind that black plastic choke cover and it relaxes. That allows the choke to further open and the mixture to normalize.

If your choke does not snap shut when cold you will have all manor of starting difficulties.

I would like to add that, if the carb is in good working order, "working the accelerator pump vigorously" does nothing but waste gas and, at the very least, make the engine run rough.

In fact, I shake my head at so-called hot-rodders who wire the choke valve open for better performance and then sit there diddling the gas pedal to try and keep the thing running during warm-up. I can't decide whether they're just too cheap or too stupid to install a manual choke conversion kit. I often wonder how much of that extra gas finds its way past the rings and into the sump, and roll my eyes thinking about what that does for bearing life. Anytime I go look at a car for sale and find the choke wired open, I just walk away.

Yet, I digress...

In ANY vehicle with a gasoline-fueled engine that's aspirated via carburetor, unless the car has been sitting so long that the fuel bowl went dry, all you should have to do for a cold start is depress the gas pedal to the floor once and release before you first turn the key. That delivers a healthy squirt of fuel down the throttle bores and allows the choke to close (under spring tension). Then, you have to give the vehicle a little bit of time to warm-up before you drop it in gear.

If you have to do anything more, then the carb is either improperly adjusted or something in the fuel delivery system needs repaired. (Just because something has been rebuilt doesn't mean it was done right.)

I've adjusted enough carbs in my life to suspect that thermostatic springs may weaken a bit over the decades (though not so much to bother with trying to find replacement parts), and I don't rely solely on the factory index marks. More often, with air cleaner removed so that I can observe the movement, I loosen the choke stat cover screws and rotate it to allow the choke butterfly valve to open completely. Then, I turn the cover in the other direction until the valve is just closed, and tighten the cover screw. The best time to do this is in the spring/fall season, when ambient temps are about midway in their annual range.

Yet, in one rebuilt carb that I was asked to inspect, the choke coil had been installed BACKWARDS!!!