70 vert, 350/350 - So here's my story. I replaced my points 5 yrs ago (please continue to read). Maybe I have driven between 750-1000 miles since. Yesterday they failed while I was driving on the expressway at 65 mph (car sputtered badly) and became stranded until my brother in law came with another set. First, shouldn't the points (from a mileage standpoint) have last longer than 1000 miles? How often should the dwell be checked (car ran fine up until the point, dwell was originnaly set between 28-30). Recommendations on brand of points you use? One last thing, the points on my distributor have the integrated condenser. Some of the vendors I have looked into for a replacement have the separate points / condenser setup. Your thoughts? Thanks !!!

 

Yes, but you may have gotten a bad set five years ago.

At tune up time. Sooner if you run into ignition problems.

Over the counter Echlin's are almost generic.

Either works.

 

It sounds as though the condenser may be the actual culprit.

 

^^This

 

Were the contacts on the point set burned? eroded? welded together?

If not, the points were not your problem.

Do you have a stock ignition coil, or did you put in a 'hotter' coil?

Do you still have the stock ignition wiring which has the built-in balast resistance?

A non-stock coil together with stock points will cause too much coil current to flow through the points. But, the most likely problem is that the condenser is shot. 5 years for a condenser is a long time. Buy separate points and condenser and change the condenser yearly, along with cleaning and resetting the dwell on the points.

 

Coil is stock - Any opinion on this replacement:

http://www.corvettemagazine.com/tech...on-conversion/

 

I just replaced my condenser and points after 5 years and about 1000 miles.. the points were burnt and were arcing I presume from a bad condenser... 11 bucks at autozone..
yes check your voltage at the coil from the ignition switch, it should be around 9.5 while running. if 12 then you have too much voltage to your coil and that will diminish the lifetime of the ignition components.

dwell should be 30, as your distributor rubs down the points bumper ( whatever that thing is called) your dwell will change and subsequent timing will change also. check it more often that once every few years.

Chinese breakerless ignition is a crap shoot.. some swear by it though.
I will stick with my points. although if I looked real close, then my autozone points are probably Chinese also.

 

And you used lube when you installed the points five years ago?

 

Yes

 

Okay so I have replaced the points, dwell is at 30, if accelerate hard, car sputters - Drive the car "normal" seems okay maybe a touch sluggish - Help !

 

Based on your OP, you drive the car about 150-200 miles per year?

The car is most likely "gummed up" from such little usage. How fresh is the gas? Do you use fuel stabilizer?


Maybe the car needs an "Italian Tune Up".........take it out and drive it easily for a while, get it good and warm, then go out on the expressway and LEAN ON IT for 15-20 miles!!

 

do you have a resistor in line, without one the points will burn as if the key was on...it should not read near or around 12 volts when running....that's only for cranking ........I forgot the actual value

also nothing wrong with unitized points and condenser

 

Please describe the process for checking the voltage at the dist side - thanks

 

Yes gas stabilizer is used and car was running perfect up until the time the points / condenser let go

 

Neither points or condensers are what they used to be. It's been a long time since cars came new with points. As far as I know, there are no USA made points or condensers. In my 64 SS I run a Pertronics electronic conversion for this reason. It's been in there for probably 8 years without a single issue.

 

1 thing you may want to look at, there is a resistor wire that reduces voltage to the points to about 9 volts. The purpose is to keep the points from burning. Chrysler cars used the infamous ballist resistor. GM cars used this resistor wire. If the wire were to fail, I would suspect you would have no voltage to the points, but if a previous owner didn't know the purpose of the resistor wire and it failed, and just used any old primary wire, well then you would be burning up points.
I mention this because my 72 had a ballast resistor sitting on the firewall and inline to the distributor. I didn't understand why this part was there, until I learned of the resistor wire and it's purpose. I guess mine had failed at some point and someone at least found a remedy to the situation.

 

I am going to say a plug wire is causing your points to fail. If you have one or two plug wires that are bad then it will cause the points to arc more and than fail. Not uncommon for a car that sits long periods of time for the plug wires to fail premature so I found out yesterday.

Different car different ignition system I had to replace all the wires on my 1992 Miata that was experienceing the same problems as you have. Only had about 10,000 miles on a set of wires that should last about 30,000 miles for the model year car. Points system cars 15,000 to 20,000 miles if I remember right between tune ups replacing everything Plugs, Wires, Points Distibitor cap and Rotor, and Dwell should be checked every 5000 miles.

Under Load the engine would sputter and make popping sounds in the exhaust system. I tested the wires and I had 2 out of the 4 that did not provide me with an OHM Reading at all. These were my bad wires. Once I replaced them went for a test drive all was well.

First I would do is pull the plug wires one at a time and use an OHM Meter to measure the resistance. The longer wires will have a slightly higher Ohm reading then the shorter wires this is normal. If the OHM meter moves around alot during the test or does not register at all this will be the bad wire causing the points to fail premature.

When I had points systems in my older cars they would last between 5000 to 10,000 miles. Also what happens if you do not grease the CAM where the points contact the shaft it will wear out the plastic that contacts the shaft.

Another problem that comes into play on an older engine is the distributer bearing if it is worn out you will be able to time it then it will move. Inconsitant timeing could be a result of a worn out distibitor shaft. About 80,000 to 90,000 miles on my older cars I had to replace the entire Distributer happened on a 1972 El Camino and a 1976 Chevelle.

 

The [internal] harness balast resistance wire is not there to reduce voltage. It's there to limit current flow in the ignition system. If you don't have the resistance wire in a 'points' ignition system, they will see excessive current and (eventually) fry the points...maybe fry the coil.

 

Do this and be done NCE. http://www.corvettemagazine.com/tech...on-conversion/

Even my 1948 ford tractor has been converted, points are what are scored in football games

 

I have to agree on the conversion from points to an electronic style ingition system it will increase the maintenance of the system to at least 30,000 on older cars. Which is what the early model GM HEI Systems suggest. replace everything in the Cap, Rotor, Wires and Plugs every 30,000 miles. Todays ignition systems have the Coil right over the Plugs which is why they suggest every 75,000 to 100,000 miles there is very little resistance when the Plug fires and it cuts down the maintenance intervals. I still replace my plugs on my Mazda3 about every 50,000 miles and use Platinum Plugs that do not require gapping because they use 4 contact points. Iridium plugs last about 100,000 miles these days. They have come along way from points systems over the years.