conversion kit to electronic points

[cocobonks]

1986 Bayliner with a volvo penta 225D V8 GM block. Marina converted my points to electronic points, but I had some other problems with the boat and was not able to use it for awhile. Now I have the boat back in the water and running and it runs ok but after a while it begins to spudder at higher rpm's. I bought a new coil on the advice from someone who suggested that is the problem because they left my key in the run position when they winterized it last year, it maybe or not be I have not installed it yet. My question is: should the Marina have removed the resistor when they converted it to electronic because it is still on? Does the electronic point system require a full 12 volts always?

 

[Scott Danforth]

depends on what they installed.

Also, check your cap and rotor. if there is any corrosion, it will cross-talk

 

[cocobonks]

Pertronix kit. Cap, rotor, plugs, wires are all new.

 

[Maclin]

What version of Pertronix and when was it installed? The earlier ones did not like it when the key was left on and would either quit or be compromised. I think they had it sorted out with the Pertronix II or Igniter II or similar.

Also if it is not wired correctly, like say powered off the positive coil wire they will act like that.

Also if a coil is meant to have an external resistor and gets hooked up without resistance that is one of the symptoms.

Also if a coil is wired backwards that is one of the symptoms. They can still spark like that just not much juice, ask my brother how "we" know that

 

[cocobonks]

I'm not near the boat until Friday so not sure which one they used, but I do know the coil says to be used with resistor. If my memory servers me correctly there is a wire coming from the ignition into the resistor then spliced up to the positive terminal of the coil. on the neg. side of the coil there are two wires one goes down to the resistor then spliced down into the distributor, the other wire on the neg. side of the coil is black and maybe for the tack? is this right?

 

[cocobonks]

Update: My coil is putting out the right amount of ohms 1.5 on primary winding and 10.000 on the secondary winding, there is still a possibility that it is acting up when it gets hot. I checked my voltage coming into the resistor from the ignition with the key on and I get 12.6 volts, coming out i'm getting 6 volts should I remove the ballast resistor? with the motor running i'm getting 14.36 volts at the alternator but when I check it at the resistor or the coil I can't get a steady reading it just keeps jumping up and down? Help!

 

[bruceb58]

Personally, I would have just switched to a Delco Voyager distributor or left in the points.

Your voltages are normal.

 

[cocobonks]

Thanks for your response. Believe me I have thought of going back to my points! Is 6 volts enough for electronic ignition? Why is the voltage all over the place at the coil when the engine is running?

 

[72fj40]

I just installed a petronics kit in our boat 2 weeks ago. It's very easy to install. Our coil runs without a resistor the petronics unit hooked up on the neg and pos side of the coil. There was another wiring diagram for a coil with a resistor in the instructions. If I were to guess, the petronics blk wire would hook to the neg side of the coil(getting the signal from the dist) and the red wire would go to 12 volts from input side of the resistor. I can take a look at the diagram tonight when I get home.

 

[Maclin]

Thanks for your response. Believe me I have thought of going back to my points! Is 6 volts enough for electronic ignition? Why is the voltage all over the place at the coil when the engine is running?

Depends on what terminal you measure it at, and if points are open, if distributor is turning, etc.

No, 6 volts is not enough but I doubt if measured correctly that is what you will have.

A coil is a transformer, has Primary windings and Secondary windings. The positive and negative terminals are connected to the Primary, positive is from ignition and negative goes to the points. The high tension Coil wire connected from the coil Tower to the distributor cap center is from the Secondary coil. Way more windings in the Secondary than Primary. With key on and engine turning the coil is constantly getting grounded and ungrounded, once per firing of each spark plug, thru the negative terminal. That is what the points do, 12v is there while the points are closed. When they open, the magnetic field in the Primary coil collapses across the Secondary coil producing much higher voltage due to the primary to secondary windings ratio but less current. That is the energy that eventually generates the spark at the plug gap after routing from the coil thru the distributor cap and on to the plug.

The duration of the voltage build up and subsequent spark potential is tuned by setting the Dwell on the points. Then the cylinder needs the spark at the right time, hence timing is adjusted after Dwell is set.

Same type of thing happens with the Pertronix, just replaces the points with electronic switching.

 

[cocobonks]

Maclin, when the engine is running I can only get a true reading at the alternator anywhere at the coil or at the resistor it's unreadable, I have checked over and over. Does the dwell still need to be set even with pertronix. Can you explain the proper way to check voltage when the engine is running at coil and the resistor, maybe i'm doing something wrong. Thanks,

 

[72fj40]

For a points ing. There are basically 2 types of coils. 1 requires a ballast resistor where it reduces voltage to about 6 volts. The other coil doesn't need a resistor. The reduction of voltage helps the points last longer. We installed the petronix ignitor ll, it only has 2 wires, the blk goes to neg side of coil, the red wire, in you're case, goes to keyed 12volt, which would be the 12volt side of the ballast resistor. Or I believe you can purchase the other coil and get rid of the resistor.

 

[cocobonks]

one coil has an internal resistor the other does not and can be used with or without a resistor provided it's a 12 volt coil from what I have read. the pertronix igniter instruction say for best performance to remove the resistor splice together the wires from both ends of the resistor at a single point and connect to positive side of the coil, black wire from the ignitor to the neg. because the module can get hot and quit or after a while it will start to misfire from lack of power. It also says if you're getting more than 14 or more volts you need to replace the voltage regulator or install a 1.4 ohm resistor, the resistor I have now reads 2.8 ohms, what I understand this to mean too much or too little voltage can be harmfull to the ignition module. So tried of being taken for a ride by the marina up here, every little bit helps. Thanks,

 

[Maclin]

Dwell is stamped into the electronics inside the Pertronix. Just set timing with with the distributor.

Voltmeter negative lead on the battery neg terminal or good engine ground, and Voltmeter positive lead on positive terminal at the coil will give you the voltage at the coil.

Ballast resistance or no ballast resistance is determined by the type of coil. Internal resistance coil, no external ballast, needs full 12v. External resistance coil must have ballast resistance between it and the 12v source, the ohms required varies by coil bus usually 1-2.5 ohms.

Regarding power to run the Pertonix unit, it needs a good constant 12v to work correctly. If the coil circuit has no ballast resistance then the Pertronix 12v lead can be at the coil positive terminal. If there is ballast resistance in the coil circuit then the Pertronix 12v lead needs to be connected to 12v at the key or somewhere before the ballast resistance. With ballast resistance in the circuit the voltage supply to the coil varies with temperature and coil loading, so if the Pertronix is connected there (when ballast is in the circuit) it can't behave reliably.

If a coil is designed to run with external resistance and that has been bypassed then there will be symptoms as you describe as it gets magnetically saturated, points or electronic triggering. A coil designed to run with no external resistance needs to be at full 12v or spark potential will be affected.

If your boat's 12v supply is not constant between the 12-14v then you need to look into the charging system as everything is affected from light bulbs to radios to ignition. Also moving to electronic triggering requires a good charge on the battery as low cranking speed and low voltage at the electronics is not a good combo.

 

[cocobonks]

Thanks for the explanation...Makes sense now!
One more question. I will test the voltage at the coil how you said when engine is running, what if I still get a fluctuating, and an unreadable voltage any idea what does that means.

 

[cocobonks]

Thanks for the explanation...Makes sense now.
One more question. I will test the voltage at the coil how you said when engine is running, what if I still get a fluctuating, and an unreadable voltage any idea what does that means or is that normal because the module is constantly on and off.

 

[bruceb58]

Thanks for the explanation...Makes sense now!
One more question. I will test the voltage at the coil how you said when engine is running, what if I still get a fluctuating, and an unreadable voltage any idea what does that means.

If you are running a ballast resistor, it will fluctuate. That is normal. As the electronics(the switch that replaces the points) open and close, the current goes up and down and therefore the voltage drop through the ballast resistor goes up and down.

BTW, measuring any voltage using the negative side of the coil is a meaningless measurement so don't bother.