Packard Forum Index » Post-War (1946-54)

Hi everyone

We have a 1946 Packard Clipper deluxe 8 cylinder inline.

Recently we have experienced some issues.

When accelerating from low rpm, the car wil sometimes keep cutting out until it its in the mid-range rpm's.

It feels like it's losing spark or fuel for 1/10th of a second at a time, and this will happen 2-5 times while accelerating.

I'm new on here and have tried to find prior posts with no luck.

Has anyone experienced similar issues, and have an idea of what we should look at?

Thanks in advance,

Old, stale fuel can cause problems.

Otherwise, the missing or lurching could be caused by a number of things.

If the engine is not getting enough fuel, you will often get a surging effect, perhaps with backfiring.

A more abrupt jerk or hesitation might more likley be a problem in the ignition system.

If the car runs well most of the time, it's probably not a serious issue.

Spark plugs that need attention can cause such problems, as can dirty or corroded ignition points.

Spark plug wires can cause problems if they are old, especially if they are gathered into a harness of some kind.

Sticking valves is another possibility, and it could be related to stale fuel.

If you're not certain that the fuel is fresh, draining the tank and putting in ten gallons or more of clean fresh fuel may be helpful. Always use due caution when handling gasoline. Work outside when handling gasoline.

If the oil on the dipstick is thick and dark, it would be a good idea to drain and replace it, preferabley when the engine is warmed up. A good quality 10W30 oil is suitable.

Also check the distributor. There is a fabric covered wire inside some distributors that can cause intermittent problems and symptoms like you describe. Worn shaft bushings can also lead to some intermittent ignition issues if the wear is bad enough to let the shaft wobble enough for point gap changes.

On the wire issue, if you have the type distributor where the vacuum advance rotates the entire round dist body, that fabric covered wire may not be present or will not likely be an issue. Do check the condenser wire though just to make sure it is not rubbing or pulled tight against anything that moves.

If you have the type distributor where the vacuum advance moves the breaker plate inside the distributor, there is a very flexible fabric covered wire that connects the inside points and condenser terminal connection to the terminal located outside the body where the coil connects. The fabric insulation can rot and fall off the wire and as the breaker plate is moved by the vacuum advance, intermittent shorts can occur causing the engine to misfire. As the engine starts to act up the advance moves the plate back, the short goes away and all is well again. If a large enough chunk of insulation falls off there will be a dead short and the car will not start.

In some distributors the wire is easily visible but on others it can be held by clips under the breaker plate. On those hidden wires it is hard to see all the wire to know if there is a problem. If you do find a wire with bare spots DO NOT use fairly stiff hookup wire as a replacement or tape that will stiffen the wire. The continuous back and forth motion of the breaker plate will soon cause ordinary wire or a long stiffened area to break. For the distributor application it must be a very fine multi-stranded ultra flexible type wire, preferably with crimped on terminals so no solder can run back in the wire to make it stiff at the ends. Search for ground lead wire. Various lengths and terminal configurations are available so try to find something close to what you have. Some parts stores will still have them and there are ebay vendors that sell them too.

I'm inclined to think that I would sort out the ignition first. Most of my cars that ran poorly had issues traced to ignition. I went through my '46 Deluxe ignition last year and whereas it was pretty good beforehand, it seemed a bit perkier afterward.


Only then would I look into fuel problems.

Hi, thanks for the quick reply!
Spark plugs are new, and recently components in the ignition were replaced.

Thanks for all the answers, I'll look further into the ignition system.

Also, fuel is not more than 6 months old, and probably newer.

Car is not backfiring. Has a slight tick, but not so much that I'm worried about it. Oil was recently replaced.

Driving the car may do it as much good as anything, if it has been sitting.

Fuel can go bad in as little as 30 days.

Fuel may go bad faster in an older car with an atmospheric fuel system than in a newer one with an non-vented system.

Some metals found in older fuel systems may react with modern fuel over time, especially if any trace of moisture is present.

More than once, I have found that problems with a car were caused by what everyone knew was not the problem.

Carburetor accelerator pump/plunger? Easy enough to check if it is working. With the engine off and choke plate open and looking down into the throat of the carb, work the accelerator linkage to see if there is a stream of gas being pumped. Should be two streams as there are two jets.