I have a stock 1.7 with d-jet, that goes thru points every 400 miles (guesstimate). It runs great then starts to get a bit of stutter at misc. rpms. First time I replaced the points because they were pitted, fixed the problem. It is back again, and the points look the same as last time.

Coil is of unknown age and condition. Could a weak coil cause this? The first time this happened I had recently been trouble shooting some dashboard electrical issues and thought I may have left the key on causing the pitting.

Thanks for the help,

Jim

Put in a new set of points AND a condenser. The condenser is there to keep the points from burning up and pitting.

Clays right of course.

Other things to think about. Leaving the key on could cause problems with your points. If they are closed you have a lot of current from the battery through the points, through the coil and straight to ground. If you have a stock coil with 3 ohms on the primary then you will get 12v/3ohms = 4 amps of current. Some of the aftermarket coils go down as low as 1 ohms - that makes for 12 amps which is a real whack of current. If your points happen to be just barely making contact or a tiny spark gap you have yourself a pretty good arc welder.

so:
points and condenser always are replaced together.
If the key is going to be on for more that a few seconds lift power to the coil.
Measure the primary of your coil. If less than 3 ohms get a new one or add a ballast resistor.

Check the voltage going to the points. You should have 6 volts I think. I installed a Blaster coil in one of my BMW's and needed to add a second resistor to keep the points from frying. Your unknown coil may not step the voltage down or may be for breakerless ignition.

Thanks for the input. I do replace the points and condenser as a set. I will measure the resistance of the coil.

Where would a resistor be located if used/needed? just inline from the coil to distributor?

Thanks,

Jim

Yes

a coil wired backwards can cause this as well

Actually I think it goes on the 12 volt feed to the coil. The resistance measurement is between the + and - leads.

The stock coil has a resistor built in--or at least, as much of a resistor as is needed for a stock system.

Dirt on the points (especially oil) can also cause problems... Make sure your feeler gauge (or whatever you use to set the points gap) is clean.

--DD

Are you using anti-seize on your spark plugs??? Don't laugh!