Fixing Vintage Chrysler, Plymouth, and Dodge cars (with carburetors)
Ignition and electrical repairs for vintage cars
FOCUSED ON PRE-1960:
Check out these excellent articles with illustrated how-tos by Mopar Action's Rick Ehrenberg:
A reader wrote: "The heat riser/flapper was stuck closed in my 273 V8 manifold. The car was lacking power and ran on the warm side."
DuraBrake has re-manufactured the Bendix rotors for the
B-bodies including the 1966-1969 Dodge Coronets and Chargers, Plymouth
Belvedere, Satellite, GTX, and Road Runner. This is the rotor only, for the two piece setup. Contact DuraBrake at 650-210-9315 x109.
Bob Lincoln wrote that to fix it, "I took the manifolds off and pried with a tire iron on the flapper with all my strength. No amount of any penetrating oil (including Chrysler solvent) would do. ... It's the shaft that sticks. It's supposed to rotate, but years of carbon will weld it in place. In the late 1970s, Chrysler switched to teflon-coated shafts, which helped tremendously."
"68RT" wrote,
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.
Various problems
Numerous and unexpected problems may be caused by leaking vacuum hoses or mechanics
disconnecting your vacuum hoses. 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.
Transmission noises
The owner of a 1967 Dodge Coronet wrote, "My A-727 has a static leak in the front of the transmission. An unrelated problem is that, at high idle, if I put the shifter in reverse, I get a buzzing sound and no reverse engagement. This has only happened twice and I immediately threw it back in park and did not put it in reverse again until I kicked it down to slow idle. It then went into reverse just fine." TorqueFlite expert Tom Hand replied:
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.
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. "
Speedometer repairs
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."
Transmission vibration
Rick Jenkins said he had a lot of vibration at 48 mph and above, despite new tires; the vibration was felt in the car, not just through the wheel. He investigated and found up and down play in the driveshaft where it went into the transmission; the U-joint was fine. He was told if the rear seal on the transmission wasn't leaking, it was fine; he had the driveshaft checked for balance (based on advice from the forums) and "it was so far out of balance, they couldn't get it within specs;" he ended up getting a new driveshaft, and a rear transmission mount. The combination of both was causing the vibration.
Runs rough cold, seems to improve with heat
George Young suggested: "Not enough voltage from the old, damp coil? Try a new coil. Check to make sure the EGR valve plunger is not binding open; remove and plug the 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...
George Young added: 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)
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. Chrysler 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!)
Timing marks and removing the crank seal
The timing marks are located on the lower driver's side of the timing chain cover. If the car has extra brackets bolted on the bottom of the timing chain cover, they may hide the timing marks from being easily seen. Some early LA engines may have had the timing marks on the passenger side but certainly by 1977 they should all be on the driver's side. (Thanks, valiant67)
When the timing chain cover seal is leaking, the harmonic balancer will need to be removed. It will require a 1 1/4" socket and a puller to remove the balancer. You will then be able to replace the crank seal (and maybe add a wear sleeve to the crank if the surface is worn).
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.
Fuel boiling
Boiling fuel on hot days has been a common problem and there are numerous discussions of solutions. For the slant six, Scott wrote:
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:
Provided by an anonymous reader, who checked what he could but warned, "There might be mistakes or errors."
We strive for accuracy but we are not necessarily experts or authorities on the subject. Neither the author nor Allpar.com / Allpar, LLC may be held responsible for the use of the information or advice, implied or otherwise, on this site. This page is offered "as is" and without warranties. By reading further, you release the author and Allpar, LLC from any liability.
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We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.
Ignition and electrical repairs for vintage cars
FOCUSED ON PRE-1960:
- Electronic ignition system replacement - for 1970s-1980s cars and trucks, and for cars and trucks that came with points (from Mopar Action)
-
-
- EGR system replacement on a budget
- LED replacement bulbs tested/reviewed
-
- Bright headlights: dramatic, low-cost gains with relays
- Adding DRLs to vintage cars
- Rebuilding distributors
- 8-track tape decks
-
- Front end alignment tricks, tips, and specifications
- How to swap in a police firm-feel chuck and get rid of steering slop
- One Lap of America in a Plymouth Valiant | Preparing the "One Lap" Plymouth Duster
- Installing and caring for inner tubes
- Converting to disc brakes; disc brake repairs
- Restoring and tweaking 4-piston disc brakes (1965-1970s)
- Mechanical fuel pump repairs
- Vacuum gas tank repairs
- Carburetor rebuilding: a primer and guide
- Fixing fuel evaporation control systems: Solving hard starts and "that gas smell"
- Tuning the 1963-69 vacuum advance control valve for better power and economy
- High-performance oil pumps for classic cars
- Cars that won't start
- Flathead six troubleshooting
- DIY EGR repairs
- Speedometer repair
- Windshield wiper linkage repair
- Adding shoulder belts to vintage cars • Upgrading seat belts on vintage cars (Valiant.org)
- Putting miles on the vintage iron: daily driving the classics
- Car fires and fire extinguishers (via Skinned Knuckles)
- See the Imperial Club's transcriptions of Master Tech books, 1947-1973, for all Chrysler brands, with sixty movies.
- Adding seat belts:
- 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.
Check out these excellent articles with illustrated how-tos by Mopar Action's Rick Ehrenberg:
-
- A head for our time: A look at the latest cylinder heads for your Mopar
- Tech analysis of the 4.7 liter V8 engine (1999)
- 440 Six Pack - Chrysler's Ultimate Street Motor
- TTI X-style exhausts: pick up an extra 24 horsepower
- Bolt-on performance upgrades including some cheap fixes
A reader wrote: "The heat riser/flapper was stuck closed in my 273 V8 manifold. The car was lacking power and ran on the warm side."
DuraBrake has re-manufactured the Bendix rotors for the
B-bodies including the 1966-1969 Dodge Coronets and Chargers, Plymouth
Belvedere, Satellite, GTX, and Road Runner. This is the rotor only, for the two piece setup. Contact DuraBrake at 650-210-9315 x109.
Bob Lincoln wrote that to fix it, "I took the manifolds off and pried with a tire iron on the flapper with all my strength. No amount of any penetrating oil (including Chrysler solvent) would do. ... It's the shaft that sticks. It's supposed to rotate, but years of carbon will weld it in place. In the late 1970s, Chrysler switched to teflon-coated shafts, which helped tremendously."
"68RT" wrote,
Power loss can also come from fuel boiling in the line (which also makes a noise that sounds like pinging). See the Carburetor section near the bottom of the page.
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.
Various problems
Numerous and unexpected problems may be caused by leaking vacuum hoses or mechanics
disconnecting your vacuum hoses. 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.
Transmission noises
The owner of a 1967 Dodge Coronet wrote, "My A-727 has a static leak in the front of the transmission. An unrelated problem is that, at high idle, if I put the shifter in reverse, I get a buzzing sound and no reverse engagement. This has only happened twice and I immediately threw it back in park and did not put it in reverse again until I kicked it down to slow idle. It then went into reverse just fine." TorqueFlite expert Tom Hand replied:
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.
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. "
Speedometer repairs
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."
Transmission vibration
Rick Jenkins said he had a lot of vibration at 48 mph and above, despite new tires; the vibration was felt in the car, not just through the wheel. He investigated and found up and down play in the driveshaft where it went into the transmission; the U-joint was fine. He was told if the rear seal on the transmission wasn't leaking, it was fine; he had the driveshaft checked for balance (based on advice from the forums) and "it was so far out of balance, they couldn't get it within specs;" he ended up getting a new driveshaft, and a rear transmission mount. The combination of both was causing the vibration.
Runs rough cold, seems to improve with heat
George Young suggested: "Not enough voltage from the old, damp coil? Try a new coil. Check to make sure the EGR valve plunger is not binding open; remove and plug the 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...
George Young added: 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:
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. Chrysler 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!)
Timing marks and removing the crank seal
The timing marks are located on the lower driver's side of the timing chain cover. If the car has extra brackets bolted on the bottom of the timing chain cover, they may hide the timing marks from being easily seen. Some early LA engines may have had the timing marks on the passenger side but certainly by 1977 they should all be on the driver's side. (Thanks, valiant67)
When the timing chain cover seal is leaking, the harmonic balancer will need to be removed. It will require a 1 1/4" socket and a puller to remove the balancer. You will then be able to replace the crank seal (and maybe add a wear sleeve to the crank if the surface is worn).
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.
Fuel boiling
Boiling fuel on hot days has been a common problem and there are numerous discussions of solutions. For the slant six, Scott wrote:
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:
Driveshaft list / transmission / rear axle list
Provided by an anonymous reader, who checked what he could but warned, "There might be mistakes or errors."
We strive for accuracy but we are not necessarily experts or authorities on the subject. Neither the author nor Allpar.com / Allpar, LLC may be held responsible for the use of the information or advice, implied or otherwise, on this site. This page is offered "as is" and without warranties. By reading further, you release the author and Allpar, LLC from any liability.
Home •
Engines •
Reviews •
Chrysler 1904-2018 •
Upcoming •
Trucks •
Cars
Spread the word via <!--Tweet or--> Facebook!
We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.