R16 burning through points

[johnlorio]

My 67 SSS with an R16 is burning through points -we’re on a he 4 th set in just a few hundred miles. We recently installed a 280zx alternator that is putting out 14.7 volts. Can we be sending too much voltage through the ignition?

I’m about to install an East Coast Roadster electronic dizzy and I’m afraid of damaging it.

[notoptoy]

John:
What coil do you have in the R16? Does it have a ballast resistor? If like a standard Roadster, you should be getting about 8 Volts at the coil. Anything much more than that and you will burn out the coil, and the points. Check for a good ground wire to the points and that your screws are all tight. 14.7 volts out of the alternator is too much, and sounds like your voltage regulator is not functioning properly. Does the head light brightness vary with engine speed?

[johnlorio]

Thanks I’ll work those options. I haven’t measured voltage across coil so will do that

[jrusso07]

Also, replace the condensor. It extinguishes the inductive voltage spike (back EMF) when the points open.

[keith0alan]

The two top possibilities are bad condenser and lack of ballast resistor.

[redroadster]

High amp coil would be another ...stock coil?

Back in the everything had points days
Mechanics had there brand of points they liked /wanted to use it was tough trying to get them to put a different brand in

But should be no prob. with the aftermarket dizzy

[johnlorio]

Thanks, just got back into town and I'm going to check ballast and condensor, but more to understand what's going on as the E Dizzy should remove them from the system. What resistance across the ballast is good? I've read 3 ohms -

How do you check the coil? I think theres a primary and secondary voltage, one across the terminals and one to the dizzy, ?

[redroadster]

Stock coil or looks like it ?. many performance coils say there output...they're proud of it
Check the resistance of the points if they have any it will heat them up

Ever try this on used points ?
File the worn pts with a point file smooth and clean new steel which takes away the silver or like coating ...they will rust now...but rub silver solder into the points file ,then file more when it fires up it puts a coating of the ss back on the points. or you can use the brass or stainless wire wheel on the contacts. It usually got me thru the rest of the season

[jrusso07]

Primary voltage is 12v, secondary with be very high voltage; 20 to 30 thousand volts (more like jolts). The secondary voltage is the high tension wire from the coil to the distributor.

Primary resistance is very low, like 0.2 ohms, secondary resistance is like 10,000 ohms.

Really hard to check a condenser as it is a capcitor. When you connect your ohm meter, it will look like a short at first jntil it chrges up. Still hard to judge goodness. Best to just replace it with new.

[notoptoy]

My recommendation if you’re going to stick with points Is to buy two or three or four condensers. They tend to go out at the most inopportune times and I’ve had brand new ones fail right out of box.

[redroadster]

Primary voltage is 12v, secondary with be very high voltage; 20 to 30 thousand volts (more like jolts). The secondary voltage is the high tension wire from the coil to the distributor.

Primary resistance is very low, like 0.2 ohms, secondary resistance is like 10,000 ohms.

Really hard to check a condenser as it is a capcitor. When you connect your ohm meter, it will look like a short at first jntil it chrges up. Still hard to judge goodness. Best to just replace it with new.

You can always take the condensor out , on another car take the coil wire out enough, running to where it arcs then touch the wire end of the condenser to that arc .( carefully holding by the insulated wire only ...cant emphasize that last part enough )...now the fun begins ....set it down on the shops parts counter and ask a guy / other mech if that conden. looks ok ...if he carefully picks it up by the wire and sets it back down the same way ., says looks good to me ..he has had it done to him before
Especially recomended for service writers who screw you over on a reg basis.

[johnlorio]

I"m only getting .7 ohms across the coil and the ballast is a 1.5 ohms, so seems low - like a mismatch between coil and ballast. expecting a 1.5 ohm across the coil

[redroadster]

Work on or replace points first check ohms
1 ohm touching leads ?
Coil has the 300ft of wire to go down

[johnlorio]

OK replaced all the ignition system with East Coast Roadster electronic ignition and coil - all new. Dramatic improvement but instead of getting a miss on acceleration (that now happens very nicely), I get an occasional backfire when traveling steady state and lifting off the throttle - seems to be in the exhaust rather than the engine (previously I could see smoke when misfire from the carbs, not now). I'll check timing again and the vacuum advance to ensure I'm getting a tight seal around the hose. I also suspect the carbs are running a bit rich - any ideas?

[Linda]

Did you get new spark plug wires? The larger size is often recommended.
I have gotten a miss when the wire terminals at plug, cap or coil have started to break. More prevalent with an MSD system.
The EI dizzy is a great product. Get a spare module.
Linda