What Is Wrong With My Plymouth Duster?

Question

Car: 1971 Plymouth Duster, Slant 6

Symptoms: I pulled off the freeway one night, and as I was coming to a stop, the engine stalled. It started up after sort of a struggle.

The car ran fine for a few more days. I thought it just needed a tune up.

Then, the car started stalling and running rough, then stalled and I couldn't start it.

I thought it was the fuel pump, so I replaced it. That wasn't the problem; the carburetor is getting gas.

I dumped a few cap fulls of gas down the carburetor and the engine doesn't turn over.

My God! What could be the problem?

I just replaced the points and condenser, it didn't start.

I then replaced the ignition coil -- still it doesn't start.

Answer 1

Check your ignition system.

Some folks will say points, but I'm pretty sure that 1971 was the year DCP (Dodge/Chrysler/Plymouth) made electronic ignition standard on all models. There are so many different things to check- coil, wires from the coil to the distributor (and or electronic ignition module)

There's also the possible issue of the timing chain- especially if it's never been changed on this car. DCP used plastic cam gears that disintigrated over time.

Get someone who knows what they're doing to check this out for you- otherwise you may cause more problems in you attempt to figure it all out.

Good Luck.

Answer 2

With fuel in the carb, it kinda sounds like it is spark.

By not turn over, I assume you mean doesnt start. If it isnt cranking over, then it could be anything from bad starter relay, to bad solenoid , a burnt out fuseable link or a bad starter.

If it is turning over, then start by checking to see if you are getting any spark at all. The 71 would have a point ignition. Check the points, if they are burnt replace them and the condenser. If not, make sure they are at the correct gap.

Check cap and Rotor for wear or oxidation. If you havent replaced them in a while, now would be a good time. Besure to put the plug wires in the same place on the new cap.

Still not running? Could be coil, or ballast resitor. I try to have a spare or old one around the garage, that I can swap in to see if it fixes the problem. If you dont have that option, start with coil then resistor.

These old cars, you can do a lot of your own work. Would be good if you have a neighbor or friend who can help you out that has checked these things before who is mechanically inclined. You could also try moparts.

Answer 3

"I dumped a few cap fulls . . ." I assume you mean the engine would not run after doing so because just above that sentence you said the carb is getting gas. If you're getting gas and air, the only thing left is spark. When you replaced the points and condensor did you gap the points properly, on the high side and the proper gap . . . . been a long time . . . . .015 to .019 I think. Not suggesting you don't know what you're doing, just throwing out an idea. Slant sixes were tough engines and would run forever if reasonably maintained, but the distributor way down there on the right side, quite a reach.

Answer 4

Have you tried replacing the balast resistor? It is a small ceramic piece attached to your firewall or fender. they don't give a warning when they go bad. they just go. Fortunately, they are very very cheap. Usually around 3 or 4 dollars. Maybe that is the problem. Also check your spark plugs. If they are wet and smell of fuel, your engine is flooded. Instead of pumping the gas pedal when trying to start it, keep it pressed all the way to the floor. I know it sounds crazy but it works.don't let up till it starts. Don't burn you starter out or wear the battery down trying to do this. Give it a rest every few cranks.

Answer 5

Check the ballast resistor on the fire wall. They are prone to burn out on Chrysler cars around those year models. It's a ceramic thing with about 2 wires attached. It's used to cut the voltage down from the ignition switch to the coil. That thing on the side of the air filter can also go out too. It's what advances the timing.

Answer 6

Is is worse in wet weather? It sounds like you have multiple problems. First see if you have gas, then try spark. I would look to the distributer cap, rotor and wires, because the problems appears to be intermitttant. If you have never done this before then get some help from a good tune-up book or manual. You can fix it with a trouble shooting manual. They are free at the library. Good luck!

Answer 7

if it crancks but no start you may have flooded your engine when dumped fuel in the carborator keep cranking untill all the fuel burns, also check your engine oil and smell it , if it smells like fuel then your car has fuel mixed with oil and the car will never start even if you fix the problem untill you change your engine oil. also check for spark in your spark plugs, pull spark plug out leave it in the wire and crank the car and see if there is spark, and check the fuses . if your car run and stall , propably has something with fuel

Answer 8

Check and replace the fuel filter if not already done. Have Carb Checked and Rebuild or replace carb if needed and ck Vaccuum lines for proper connection and leaks. These are the most common causes

Answer 9

Check to make sure the the the distributor rotor turns when you turn on the starter motor.If it does turn check timing and verify spark

Answer 10

Check your timing chain and timing also check for spark.