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

All,

I have a 53 Packard with a 288. I had to replace the distributor back in the winter. Installed and it cranked right up and ran perfectly. Came back to it a few weeks later and it wouldn’t start. No spark. Found that rotor button was broken. The brass had popped out between the center and the outside contact. Ordered and it will not start. I’ve had several people help me with this problem that are not Packard peeps. Wondering if the wiring on the coil could have been incorrectly installed. Should the positive side of the coil connect to distributor or should the negative side? I put a meter on the coil with power and I get a bit over 6 volts on both sides of the coil. I have checked the point gap and have it at .017. Timing is at 6 btdc. Carb is spraying gas into cyl. Need some help

This wiring diagram should help you double check that everything is hooked up right. It's for a 26th series, but should work for what you need.

https://packardinfo.com/xoops/html/downloads/wirediagrams/1953%2026th%20Series.pdf

The coil primary connections being reversed would not affect the distributor cap or rotor. If you car is negative ground, the negative post on the coil should connect to the distributor. If it is positive ground, the opposite is true. A car will run with the wires reversed, but it will run better with them in the correct order.

The damage to the distributor cap/rotor probably has a mechanical cause. Perhaps the distributor is not seated in the block properly, or the cap or rotor isn't seating properly, causing too much pressure on the carbon button in the distributor cap or even allowing the rotor tip to hit one of the plug wire contacts. The cap not seating properly is probably the most likely scenario.

Too much up and down play in the distrubtor shaft could allow it to push against the rotor and cap when the engine is running, which could lead to early failure.

If you have 6 volts on both sides of the coil while the points are closed, then the points have become dirty and are not passing current. Clean them with some really fine sandpaper followed by clean white paper, or file them. With the points closed the voltage on the distributor side of the coil should be just about zero.

If your car is still hooked up with positive ground, then the + side of the coil should be wired to the dizzy.

The coil will work if wired incorrectly but for the most efficient spark, on a positive ground car the + (pos) terminal on the coil should go to the distributor. If the spark is slightly weak because of incorrect wiring it could make a difference if there are other issues with the engine such as dirty plugs, poor compression or high resistance in the primary wiring which can lower the voltage to the coil enough that it provides a weak spark.

If the points are open you will have approx 6 volts on both coil terminals. If the points are closed you should should have the 6v on the terminal connected to the ign switch and almost 0 volts on the terminal connected to the distributor. With points closed the closer to 0 the better but depending on how solid the ground is and if there is any wire and connection resistance it may go as high as around .2 to .3v and still work fine. If the voltage never reaches near 0 or seems erratic the ground to the distributor could be suspect or the points could be oxidized. If the key was on in the ign or run position while the points were closed for a long length of time they could also have burned slightly.

Also check the voltage feeding the coil while the starter is cranking. If there is an issue with the starter, too small a battery cable, dirty connections at some point in the wiring to the coil, or a weak battery cell the voltage to the coil could be lowered to the point the spark is too weak to jump the plug gap.

Sometimes prolonged cranking without starting can also foul the plugs so that might also be worth checking.

The starter is turning slower than what I usually expect. What voltage is required to jump the plug gap? I suspect a dead cell.

You can get another 6 volt put it in parallel.

If you need more amp boost

There is no set voltage that will allow the ignition system to work. A good guess would be 4.7 to 5 volts minimum. Ignition system condition would be a determining factor. More voltage is better, up to about 7 volts maximum.
Voltage would be measured at the battery side of the coil primary with the starter cranking. I would not connect a battery charger to the coil primary to boost voltage.

Many later cars have an ignition resistor cut-out that bypasses the ignition resistor when the starter is engaged. Some have a switch built into the ignition switch, and some have a contact on the starter solenoid or starter relay that bypasses the resistor. If the resistor bypass system is not working, it can make starting difficult, especially if other parts of the starter and ignition system aren't working at 100%.

If your starter is cranking more slowly than usual, look for problems with the battery state of charge, battery condition, any and all electrical connections in the starting circuit, including engine to frame grounds, and if all that is 100%, a problem in the starter or starter soleniod is indicated.

Make sure you are running 6v battery cables, not the thin 12v ones. Ideally, they should be close to 00 or 0/1 gauge.

Also, verify battery ground strap is attached to the motor and not the body.

I wasn't too concerned with a conductor popping out of a rotor. I've had new out of the box do that, but when you put a good one back in, it runs. So something else is faulty. The question is what?
Anything else changed or worked on during this time?
What's the history of the "replacement" dist? Was it verified to be the same #? Was it checked for runout or any other condition to verify it's good. Correct drive gear, not worn? Not many distributor machines left but they are still around, if you can find someone who has and knows how to operate correctly and check it out.
If you have a induction timing light you can check each wire to see if it's sparking. May have to connect gun to a 12V source, if a 12 V unit, but the pickup should fire the light on a 6V. Usually, I find when they won't start "at all" and the dist was out, it was put back 180 out, so may need to check the timing to TDC compression.
to your question:
The spark is not happening at battery voltage. The battery voltage goes to the one coil to induce a greater voltage in the other coil for the ignition. Something in the neighborhood of 30-40K + or - volts is needed to jump the spark gap in the low compression points era. {Spark energy needs to increase with increasing compression.}
I always troubleshoot with a new or good battery, so that's taken out of the list of possibles. At least take it out and charge it fully and take to local auto parts chain store have have them load test - free usually.