1940 Seems to be running on six cylinders

[West Peterson 784]

I'm not very familiar with working on these (more involved with Packards). However, this one apparently belongs to me now, and while I brought it home almost a year ago, I haven't had any chance to do anything with it, let along play with it. Today, I wanted to make sure there was enough antifreeze in it, so took it out for a drive to put in fresh gas, etc. It seemed to run and idle just fine, other than it seemed like it was only firing on six cylinders.

 

Is this a common problem? Is there something I can try easily, before removing the distiributor? I made sure the covers were on tightly, but that's about the extant of my ability at the present time.

[West Peterson 784]

Seems to idle just fine, only has problems upon acceleration. Maybe carburetor needs to be gone through?

[Ray500 24]

You really need to go through the ignition system including plugs, wiring, distributor issues, fuel issues with the carb!   If you're not familiar with the V12 the you need to send the distributor and coil to Skip Haney in Florida to have him check it out, repair as needed and reset the distributor as it requires a machine to do it off the car.  The old coil....the black device sitting on top of the distributor can be rebuilt with new coils, and the rest of the distributor can be repaired and reset.  Also get new spark plugs and plug wires.  Plugs can be obtained at Napa and such, the wiring sets from Rhode Island Wire will work well.  There are people who will repair the carb too and put in parts that tolerate ethanol (alcohol) in today's fuels.  Once that's all done and working you can then see if that fixed it, or do you need to look further at the valves and engine compression tests.  Perhaps you can find a good mechanic in your area to help, but most of the good ones are gone!  These younger guys don't really understand these flat head engines with hydraulic lifters.  Lots to think about!  Good luck!

[West Peterson 784]

Thanks, Ray. It was running fine (or so I'm told) before it was stored for a year. Spark plugs look brand new, as do the plug wires. I drove this car on the Glidden Tour in Tennessee/Georgia several years ago, and at that time we took off the distributor (Honest Charlie's Garage in Chattanooga), and they did a pretty good job of getting me back on the road without any more problems. I suppose its possible that the distributor is still giving us more problems. Sending it to Skip Haney sounds like a good idea. Will check out possible carburetor troubles first.

[zephyrdave 21]

Not bad idle, but sluggish acceleration can be bad coil on one side. There are two coils in one assembly, one for each side of the engine. Pull a plug wire off on one side of engine and hold close to plug with insulated pliers. Have some one start the car and see if there is a spark. If no spark, try the plug beside it. If still no spark, then the coil that serves that side of engine is dead. If there is spark on that side of engine, then try the same on the other side of the engine. I had this happen on my car. One side of the coil assembly went dead. Just something to try first before a big cash outlay to fix a bunch of things that might not need fixing. 

[38ShortopConv. 26]

Do you have spark at all plugs?  One set of points may have  corroded or a points spring arm is  broken or sticking  after sitting for a while or a condenser could have developed a short causing engine to run on 6 cylinders, if in fact it is. Does it rev. up from idle freely? Lincoln Zephyr V12s have 2 sets of points and  2  condensers, one set  for each 6 cylinders. The points arm has been known to snap and become inoperable.  Also you may have a fuel jet blockage in carb, there are 2 main jets in there, one for each bank and/or  you may have old/bad fuel in tank!
Interesting gear change pattern .What about a W/W II  GMC. truck  gear shift pattern?  

Edited January 10 by 38ShortopConv. (see edit history)

[abelincoln 16]

All of the above are likely suspects.  You can check the points at the screw terminals on top with a dc volt meter.  Should have 2-3 volts when running,  Just keep fingers away from fan.  If one side says 6 volts or 0 volts you can suspect a problem.  I like to use a timing light on individual plug wires to avoid shock.  Otherwise, hook up a spare spark plug with a clip -clip on the ground electrode and watch for spark.  Lincoln distributor is an elector-mechanical marvel.  Engine is odd fire, and each set of points fires three cylinders on each side.  Nice looking vehicle.

Abe

[West Peterson 784]

Thanks for the advice everyone.

 

[West Peterson 784]

On 1/9/2021 at 7:06 PM, 38ShortopConv. said:

Interesting gear change pattern .What about a W/W II  GMC. truck  gear shift pattern?  

 

I believe it is unique to the 1930-31 Packards. First gear is a stump-puller, except if your car is equipped with the 3:31 rear-end ratio (which ours is). Otherwise, many many many 1930-31 Packard owners aren't even aware that their car has a first gear, as you have to move the shifter to the left and down to find it. Most start out in second, even if they DO know about the first. The 1930 Speedster is the ONLY model that used the 3:31 rear end, and I find that starting out in second is a little hard on the clutch.

[dl456 58]

West,

One possibility that I did not see discussed. There are two ignition resistors under the dash to the left of the

steering column mounted to a junction box. They reduce the voltage to the coils.

I have found these open (no voltage to the coil.)

If the car was running good before being parked, this is a likely suspect.

Dennis