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

Check the plug wires:

THis is important!!!! Any two CONSECUTIVE fireing cylinders should NOT have the plug wires touching each other at ANY point. There should be at least a 1/2" distance between any 2wo such plug wires. Also make sure that the coil wire is not touching any of the plug wires. If it must touch then pass it at rite angels TWICE. i.e. crossing at one point at a rite angle and then crossing back in the OPPOSITE direction at a rite angle. BEst to not have them touching.

Does the rotor button have a hammer head shaped contact out near the end toward the cap posts or is it just streight???

You mentioned that you've got new spark plugs (and new leads??). As nearly everything else has been suggested, try swapping the plugs (and leads) with others. I've fitted a brand new set of plugs on one occasion and one (brand new out of its box) was a dud plug which misfired depending on engine speed.

The statement above that two consecutive firing plug wires should not touch, but if they do they should cross at 90 degrees does not appear in any factory or aftermarket service manual I've ever seen. It also does not seem logical. A 15,000 volt wire when crossing another wire does not know its own orientation.

Picture a 28-39 Senior car, Eight, Eight Deluxe, Super 8 or V 12. The high tension spark plug wires ran in metal tubes and the wires were PARALLEL, impossible to have them at 90 degrees. AND THEY TOUCHED!!

48-54 they went through a rubber block below the coil and many of the wires touched.

AND PACKARDS WERE THE SMOOTHEST RUNNING CARS ON THE ROAD.

Lets try to keep the advice given here limited as much as possible to verified sources and keep the clothes pins on the clothes line.

Last I checked the world was still round

When all else fails, read the manual. Works well when assembling a gas grille or diagnosing a Packard. Works even better if you read it first.

Car running out of power before it reaches top speed
From the 51-54 Factory Manual, I'm sure all other manuals have the same suggestions:

Timing
Advances
Point gap and condition
Plugs
Ignition wires
Coil weak
Carb linkage adjusted wrong
low compression

MY ADDITIONS:
Choke not opening
Manifold butterfly stuck closed
Restriction in mufler/exhaust system
Air cleaner dirty/restricted

This note is for Ross:

I was looking at distrubutor specs in the Packard manual.

For the AutoLite distributors they show 27 degrees dwell.

For the DelcoRemy distributors they show 21-30 degrees dwell. I don't know what that means. Does that mean a steady dwell anywhere between 21 and 30, or a dwell angle all over the map?

I have an electronic dwell meter that I don't use very often. I will test it out and see how it does.

The kernel of the argument here is that the timing light should be steady and consistent. If it varies a lot then the distributor is probably shot.

To quote Kanter: Quote:


Lets keep these kinds of comments to yourself. You, my friend, are not as smart and wonderful as to think you are.
Are you a verified source?

I am not a verified source nor do I represent myself as such.

My statement is "...to keep advice..limited as much as possible to verified sources", referring to service manuals etc. Above I quoted from a 51-54 Packard service manual , then added some info from other sources.

Nowhere do I say that one should not give any information except verified sources, I just said to limit it AS MUCH AS POSSIBLE.

Fred Kanter. U are welcome to present your participation in any manner u want to. So is everyone else. THis is an INTERNET discussion group. NOT a sunday school class.

As for the spark plug wire crossing advice i gave it is certainly ez enuf to check and correct.

Plug cross fireing due to improper routing of plug wires is fairly common knowledge in the trade. IT is NOT an issue on engines with 6 or less cylinders.

Try Googling spark plug cross fireing or potential inductance.

Here's one i found quick by Jasper engines. I don;t really know it's content because my jack leg computer won;t let me download some pdf's. But here it is anyway:

[PDF] Spark Plug Cross-Fire TBFile Format: PDF/Adobe Acrobat - Quick View
NOTE: Show this TB to the person installing the spark plug wires, prior to installation, to safeguard against any future unnecessary cross-fire engine ...
www.jasperengines.com/pdf/SparkPlugCross-FireTB.pdf - Similar

Here's another one:

popularmechanics.com/cars/how-to/maintenance/1272351

About 1/3 down the screen titled "Out with the old, in with the New", 6th paragragh decribes in more detail about the plug wires crossing or touching.