Fixing Vintage Chrysler, Plymouth, and Dodge cars (with carburetors and rear wheel drive)
Also see starters, tuning carburetors, and our Mopar Action section. For slant six-specific info, see the Slant Six page.
Also see - Imperial Club’s transcriptions of Master Technicians Service Conference books, 1947-1973, for all Chrysler Corporation brands - extremely helpful! This includes no less than sixty movies.
Electrical notes
Check out these excellent articles with illustrated how-tos by Mopar Action's Rick Ehrenberg:
- Electrickery, part I: alternators and voltage regulators
- Electrickery, part II: gauges and the instrument panel
- Adding a third brake light (and making durable splices)
We have an interesting guide on electronic ignition system replacements — that is, inexpensive, complete replacements for 1970s-1980s cars.
David Pollack wrote the following about 1949-1955 headlights in the Plymouth Bulletin (reprinted by permission):
Important - David Pollack wrote, “When this article was published, we had some trouble. Apparently quartz halogen lamps were not legal in some states so a Bosch headlight was unheard of. Most inquiries came from Ohio. Also, the six volt H4 bulb was not available in Canada and had to be obtained by special order in Washington State where I purchased mine.” We suspect the headlights are now allowed everywhere but check your local laws.
The Bulls-Eye sealed beam unit (1949-1955) was an advancement in its day, but like most semi-sealed units, its bulbs would eventually blacken and moisture would dull the reflector. There is a simple cure. Find a pair of Bosch (or similar) lights with the reflectors still in good shape. They must have steel backs and take the H-4 quartz-halogen bulbs. It is difficult to do, but break out the lenses, clean up the flange, and apply a bead of windshield cement (urethane). Then, remove the lens from a bulls-eye light by carefully opening the crimped flange with a pair of diagonal wire cutters. Press the lens against the new reflector and leave overnight for the cement to harden. There is a locating slot on the reflector, and a matching tab on the lens, to maintain alignment.
Phillips makes a six-volt H-4 bulb - #6342 H 4 (6v. 60/55w). Also available is ‘Osram’ - #64190. Install the new lights in your car and aim according to the shop manual’s advice. Low Beam is now better than High Beam used to be, and High Beam is…fantastic! This method gives you up-to-date lighting with original appearance.
Car won't start
Check the ballast resistor. It's a little white block attached to the metal between the engine and the driver, with a single bolt; wires plug into each side. It's easy to replace and under $5.
If the starter makes a rapid clicking noise, your battery may be worn, even if you can see your headlights.
If the engine was wet, dry it, separate the wires, and try again, Use silicone spray or "wire drier" or, better yet, replace your wires with really good ones ($25-40 mail order). These will probably improve your gas mileage and power as well.
Dan Stern adds: Whitaker's Multi-Mag comes in the same colors and insulation materials as original, but uses the spiral-wound construction that you find in wires such as Accel and Jacobs. Lower resistance, but no irritating radio noise. They have a lifetime guarantee and don't cost more than regular carbon-string type wires. The Slant-6 wire set (32605 for pre-75) has the correct 1-piece moulded plug boots. They are also sold under the Borg Warner/BWD KoolWire name.
Many of us have found that our automatic-equipped cars would not start in Park sometimes, but needed to be switched over to Neutral. Bill Watson suggested two possibilities: the shifter linkage might be out of adjustment, very slightly.
The linkage from your steering column attaches to an "arm" that sticks out from the tranny on the driver's side. Get under the car while someone moves the gearshift linkage. This way you will be able to determine which way it goes when you put it into park.
What you do is place the car in park, loosen the bolts to the "arm", push the arm all the way in the direction park is engaged. Then push your gear level all the over the left - as far into "P" as it will go. Then tighten everything up.
The problem could also be the neutral safety switch, if it will not start at all:
As for finding the neutral safety switich, there will be a small wire attached to your starter solenoid that leads down under the floor toward the transmission. Follow this wire. You will find the neutral safety switch at the other end of it. [This switch may simply be dirty].
Note that if the problem is a burnt out coil, you can extend the life of your ignition coil by moving it to the fender or firewall, away from the engine, so it is not affected as much by engine heat. (High Performance Mopar tip sent by Erik Namtvedt)
Shakercuda wrote:
Several items will cause a no start. One clicking under the hood is the starter relay.
1. The starter has a solenoid. These will get pitted and a no start will result. A separate part of the starter.
2. You have a starter relay on the engine compartment. The connections to the relay must be tight. The battery wire leads to the relay and from the relay to the starter solenoid. These are a parts store item.
3. You have a neutral start switch on the transmission. When it does not start in park shift to neutral and try it there.
4. Check the heavy gage wire from the battery (positive and negative). The negative must be clean and tight to the engine block. The positive is hot where it connects to the starter if the wire moves under the nut on the starter disconnect the battery and then tighten.
If your problem is the starter turns the engine over but the engine does not fire:
1. The connection to the electronic ignition could have a terminal in it that is worn out or a broken wire.
2. There is a ballast resistor on the dash that could be going open during the crank cycle. It sits on the dash panel it is white in color and has two connections on it.
3. There are several connections from the ignition switch out to the ignition system, including the dash panel connector. It might be a good idea when the engine is running to just grab the wiring along the inner fender and move it around a little.
4. When the engine does not fire try turning the ignition switch to accessory and then all the way forward to start.
5. Inside the distributor is a rotor. I hope the mechanic has checked this for solid contact to the top of the distributor.
6. The distributor can have hair line cracks in it. This can be checked only when running by spaying a light mist on the cap. If you see sparks or the engine starts running rough it is the cap.
Belt noises
High Performance Mopar (tip sent by Erik Namtvedt) wrote that a squeaky fan belt can be fixed with toothpaste- put on a few dabs with the engine off. The abrasive material in the toothpaste removes glaze from the belt and pulleys, stopping the noise.
Anything from pollution to loss of power
This may be caused by leaking vacuum hoses or mechanics disconnecting your vacuum hoses. If you like to breathe, and you want your car to perform well, replace all of the vacuum hose -- it costs maybe 10 cents per foot. Just get a few yards and do it one day (warning: you may need different kinds or sizes. You may need to take bits of the old stuff into the shop). Make sure hoses are not kinked.
Vacuum leaks caused by leaking hoses that look okay to the naked eye may result in the following diagnoses by mechanics: * Need new carburetor * Need new transmission * Need new engine * Need valve job * Need new mechanic.
Stalling
See the above section on vacuum hoses. Turning the cold or warm idle screw on the carburetor is a quick fix that doesn't solve the real problem. If the car stalls when cold, lubricate the choke well. If it stalls when wet, try getting much better ignition wires (lifetime warranty, good brand, about $30). Also try: * Put window insulating tape (foam) over the top of the electronic ignition module * Spray the little wires with silicone spray or wire drier * Check for vacuum leaks (see above).
Check the choke pulloff as well - the choke may be staying closed even after the car warms up.
"65" noted: "Check the plugs at the firewall. All the power in the car goes through these plugs, and they tend to get loose and dirty with the passage of time."
Random shutoff/cutout
Random shutoff can be caused by a bad ignition switch, the usual host of electrical problems, or, according to Gary Hamel, a flaky electronic ignition module. He noted that a low-priced aftermarket replacement is available (made by Wells) at many parts shops.
Dave Schoenberg wrote that "I have had A-Bodies where the steel fuel line right out of the tank gets rubbed through just VERY slightly (I seem to remember it rubs against a shock). Just enough to intermittently suck air instead of gas. Stops for no reason and starts again when it feels like it."
ShakerCuda wrote: "You might let the vehicle warms up. Then move the wire harnesses under hood a little at a time up and down. This will duplicate what is going on as you drive with a warm engine. "
Windshield wipers / speedometer won't work
Wipers: Put window insulating tape (foam) over the top of the wiper motor to keep water out. Or try rebuilding or replacing the motor yourself. There could be many other problems, e.g. bad linkage, but the first is very cheap.
Speedometers (Jeff Voth) "Look at the back of your speedo just where the cable threads into it on the back of the speedo and there is a small metal cap that you can remove with needle nosed pliers. The cap will have some felt under it. Put several drops of 3-n-1 Oil on the felt and replace the cap. This may not solve your problem but I can [practically] guarantee that this is the first time this has been done since it left the factory."
Runs rough cold, seems to improve with heat
georgey@bnr.ca (George Young) suggests: 1) Not enough voltage from old damp coil? - new coil. 2) EGR valve plunger binding open? - remove and plug manifold vacuum hose to EGR circuit.
Dave added: Better wires, high quality rotor/distributor cap for best fit. Check the stove, that big metal thing on many engines that feeds warm air from the engine to the air intake through a usually-rotten or missing hose. The vacuum-operated flap may also not be functioning for one reason or another, usually a bad vacuum hose. This is common. Dan Stern notes the flap is controlled by the Thermostatic Air Cleaner vacuum motor...
georgey@bnr.ca (George Young) adds: My old 318 ran rough when cold and wet, would stall out until warm. Choke was the problem. Manifold carboned up and wouldn't pass heat to choke coil thermostat. Changed to manual choke and no more problem and increased gas mileage
Dan Stern noted that driveability problems could be caused by a bad choke heater control unit, which may short out and shunt full power to the electric choke, causing it to heat up prematurely.
Lean-Burn (computer-controlled carbureted engine) rough idle
(contributor name lost)
- Are your coolant temperature sensor connection ok? If not, the computer will see a cold engine and will run rich.
- Are the oxygen sensor connections ok?
- Is the heated air inlet operating correctly?
- Vacuum leaks? Check all vacuum hoses with a religious fervor! The leak's location many not even be obvious!
- Carburetor problems: float low? valve seat damage? I doubt the latter since
it appears that the problem arose quite suddenly. The following is something
I've used on computer-controlled carbureted engines many times:
Connect a high impedance dwell meter to the mixture control solenoid, set the meter to the 6 cylinders scale, run the engine around 2000 rpm until hot and see the dwell. If the a/f mixture's ok, you'll see the dwell oscillating about 30 degrees.
- Low dwell with oscillations => a/f mixture lean and running closed loop.
- High dwell with oscillations => a/f mixture rich and running closed loop.
- Dwell at or below 10 degrees => system stuck lean.
- Dwell at or above 50 degrees => system stuck rich.
The latter two extremes indicate closed loop operation since open loop operation typical will show a stable dwell reading between 20 and 30 degrees (usually, closer to 20). Do not do this test at idle since some engines will be operated in open loop at idle REGARDLESS of the coolant temperature sensor's output.
Seat belt looseness
During the late 1970s up through the late 1980s all American cars had something called a window shade mechanism to allow for a small amount of slack to build-up in the shoulder belt. This was to prevent people from complaining that their belts were too tight. I experienced (ref:June 1987 Car and Driver article by Patrick Bedard) a problem where the seat belt built up too much slack. Sometimes the belts, like a windowshade, would never return at all. There is usually a large plastic button on the 'B' pillar that needs to be fooled into thinking the door is always opened, which by the way disables the window shade mechanism and is how the belts return 'home' when you get out of the car. Cut the plastic button very close to the 'B' pillar, being careful not to cut into the inner spring Take a cotter pin and put it through the loops of the spring, this prevents the spring from ever retracting. Chrylser mini-vans are easier in that they have a rotating plastic cam with a striker pin that is engaged by the closing door. Just cut the striker pin and you eliminate the problem.
Low front end
Many late 60s and early 70s A-body Chrysler products had a problem with the rear mount for the torsion bar. Water collects in the channel and rust occurs. After a decade or so the channel that the mount is welded into rusts through and the mount twists and that side of the car falls onto the rebounce (sp?) bumper. If this is what happened you will need to find a local frame/suspension/alignment shop that has someone who has welded in new material to replace the rusted stuff and then realign the ride height when done. (Thanks, Chris Jardine).
Pinging on V-8s
Pete O Dickerson wrote: My 75 Dodge Swinger 318 would ping at part throttle operation, not at full throttle (floored!) like you might expect. Just going over an overpass or up a hill the engine would ping and clatter, even though the ignition timing and carburetor were set correctly.
The manifold was made from cast metal. The molten metal was poured into a mold through a little hole and when the manifold was finished, the little hole was plugged up with a little rubber plug. Well, after a few years this little plug would dry up, shrink, and fall out, leaving a hole in the manifold. This hole would cause a lean condition to exist at part throttle operation, by letting air leak in.
Try removing the carb and shining a flashlight down into the manifold and seeing if there is a hole in the bottom of the manifold. You can either plug it up or replace the manifold with a more performance oriented unit.
(The maintainer adds: invest in a vacuum gauge, they are cheap!)
Fast idle, then stalling.
From Timothy Economou: If you start your car and it runs for a while at fast idle and then it starts to load up and then stalls. There is this little round thing on the open end of your breather that closes the outside air when your car is at fast idle and lets it draw air from the manifold. (Stove control). Check it.
Editor's note: the stove control is frequently bad on vintage vehicles. The vacuum hose, control, and mechanics of the flap in the air horn should be checked. See above.
Poor acceleration, pinging or stumble on acceleration
“68RT:” The accelerator pump flow is seen by taking off the air filter and with the choke in the open position (engine off) you look down the carb air intake and open the throttle fully fairly fast and you should see fuel being squirted into hole(s) of the primaries. If it is weak then the engine will stumble especially if the throttle is not very slowly opened. The old accelerator pumps for example used leather for the pump seal and after 30 years they just don't do too well. (Editor's note: the stream of fuel is very obvious!)
Carburetor issues
Justin Kaszowicz's carbed 2.2 was idling rough and smoking (black smoke) when first started. The problem was that the choke was not opening - he had to open it by hand. This is a common problem. The solution in Justin's case was a new choke pulloff.
68RT wrote: If the carb has sat with little or no use, I would immediately pull the carb and rebuild it as it would be full of gum (old gas) deposits which will cause the carb to never really run right until it is cleaned up and adjusted.
Brakes
See restoring and tweaking 4-piston disc brakes (1965-1970s)
Ignition switch
Bill Watson wrote this about a 1963 Valiant, but it probably works with other models:
If you look closely at the switch in the dash, there is a bezel that screws onto the ignition switch. You will find 4 small slots on the inner side of bezel, each a quarter of the way around. I usually use a screwdriver, carefully, to move the bezel in a counterclockwise direction. Once it moves, you can undo it by hand.
Once you get the bezel off, notice that the switch has a ridge along the bottom that fits into a corresponding slot in the dash. This keeps the switch stationary while you screw the bezel on/off. Once the switch is free, you can drop the switch under the dash and pull the wire connector free.
To install, place the wire connector onto the new switch, place the switch into the dash (note the ridge/slot) and screw the bezel back on. Use a screwdriver, or some similar object, to carefully tighten the bezel onto the switch when you get it as tight as you can by hand.
Also see tuning carburetors.
Also see - Imperial Club’s transcriptions of Master Technicians Service Conference books, 1947-1973, for all Chrysler Corporation brands - extremely helpful! This includes no less than sixty movies.
Also see - Mopar Action at allpar.com for more vintage-car repair tips, disc brake conversions, and more.
